3D Shapes
Reduced Revit file size for some models containing Hermite surfaces by up to 90%.
Improved performance of some operations involving Hermite surfaces by 10% to 36% (e.g., energy analysis, opening views, and applying depth clipping to open views).

API
Fixed the computation of a stacked wall's width (i.e., the Wall.Width property when Wall.IsStackedWall is true).
Changed the API class Autodesk.Revit.DB.ParameterSet to no longer contain duplicate Parameter entries; this should improve the speed of iteration and simplify the need to deal with potential duplicates in code.
Added a new API method called "Autodesk.Revit.DB.ChangedElement" that allows users to see which elements have changed since a previous version of the document.
Allowed the use of the NewSweep API function that takes a ReferenceArray representing the sweep path to use edges as well as curves.
Implemented a new API method in SketchEditScope. StartWithNewSketch() which starts a sketch edit mode for an element which doesn't have a sketch.
For API developers who are maintaining compatible applications, the version of CefSharp has changed to v92.0.260.
Added new API to hide an individual DirectShapeType from being displayed in the type selector dialog or re-used by an existing DirectShape.

Assembly
Improved how unique assemblies containing ducts, pipes, conduit, and cable tray are determined.

Autodesk Error Reporting
Improved the user experience for instability reporting.

Beam System
Improved the response time when launching the Structural Beam System command.

Category Visibility
Enabled Cutting in View option for Furniture, Furniture Systems, Specialty Equipment, and Plumbing Fixture.

Content
Updated some existing Thermostat families to the new category Mechanical Control Devices category and relocated the file to the corresponding directory; added new Humidistat and Mechanical Control Device families to the content library.

Data Exchanges
Supported the creation of Data Exchanges in Autodesk Construction Cloud to integrate Revit data into Microsoft Power Automate flows.
Supported the creation of Data Exchanges in Autodesk Construction Cloud to reference Revit data in Inventor.

Decals
Improved Decals so that their appearance settings properly update without requiring a manual refresh of the view.

Dimensions
Added support for automatic dimension for the element with nested family elements.

Dynamo for Revit
Upgraded Dynamo Core version to 2.13, with highlights of: HIG standards applied to Dynamo UX and theme Redesigned Dynamo nodes, groups, wires interactions Redesigned Dynamo package manager interactions Refreshed UI for package manager consumer or author More package states displayed in the preference panel Package conflicts resolving improvements New notes pin, access keys support added New Dynamo guided tours including getting started and package manager for new Dynamo users Expanded workspace references panel to show local definitions and external file references New Dynamo Unit nodes based on Forge Unit SDK available OOTB IronPython, CEFSharp removed from DynamoCore, our delivery is much smaller in size thanks to this Performance improvements on node search, geometry and VM GC Detail release notes are: [https://github.com/DynamoDS/Dynamo/wiki/Release-Notes#213]
Enhanced the ability to work with analysis display in Dynamo for Revit.

Electrical Circuits
Fixed an issue causing a neutral conductor to be added to a circuit when adjusting the circuit's phase using the Switch Phases command.
Added Circuit Number property to Electrical Equipment for use in Schedules, Tags, and View Filters.

Electrical Panel Schedule
Added new API method PanelScheduleView.SetLockSlot() allowing an application to set the lock state for a circuit slot at specific cell.

Energy Model
Added Azimuth and Tilt parameters to Analytical Surfaces.
Added Analytical Space and Adjacent Analytical Space properties to Analytical Surfaces.
Simplified the analytical surfaces for curtain walls by merging the surfaces for matching panels.
Fixed an issue that caused the creation of incorrect analytical surfaces for curtain walls that are modeled inside a wall opening.
Fixed an issue that prevented the creation of an analytical surface where multiple curtain walls were placed closely inside a mass.
Added the ability to create one large opening surface for curtain walls when creating the energy analytical model.
Addressed a problem with the CADObjectUniqueId API property for Analytical Surfaces.
Improved energy analytical model creation performance in the building elements and mixed mode by up to 3x. Also, the memory footprint was reduced by up to 2x.
Corrected an issue with the OriginatingElementDescription property in the public API for Analytical Surfaces.
Removed the Use Conceptual Masses mode in the Energy Settings dialog and the same option when exporting to gbXML.
Improved the view of analytical surfaces so they visually reflect the final form of flat faces that are exported in gbXML. This is most evident for curved walls in Energy Analytical Models which are now displayed to show the tessellated polygons which are exported to gbXML and used for analysis.
Implemented automatic level assignment in the Reference Level property of analytical spaces when creating the energy analytical model (in "Conceptual Masses & Building Elements" and "Building Elements" modes) using the level which is closest to the bottom of the analytical space.

eTransmit
Added a checkbox to the eTransmit dialog to include systems analysis reports in the transmission folder.

Export DWG/DXF
Improved printing for views with Hidden Lines set to all so that Hidden Lines created by linked models below model elements in the host export as displayed on screen.

Export PDF
Enabled multiple selection and removed check all box for the View Sheet Set dialog.
Fixed an issue where Analytical Nodes were exported to PDF at the incorrect size or not at all.
User is able to use parameters or existing project browser schema to sort view and sheets in a Print set. The order will be auto-updated when the parameters change.
Added the ability to multi-select and drag in the view sheet set.
Improved the PDF Export dialog to remember the user selection in the export range.

Family
Added API for creating filled regions in 3D families.
Improved behavior when placing and editing work plane-based and face-based family to save the last used ribbon setting.
Enabled Maintain Annotation Orientation for categories:  Medical Equipment  Audio Visual Devices  Fire Protection  Food Service Equipment Signage  Vertical Circulation  Temporary Structure Hardscape
Make casework families joinable.

File Open/Save
Improved the error message and help documentation for "A fatal error has occurred."

Fill Patterns
Allowed Solid Fill Pattern foreground color overrides to work for all meshes as they already did for Fabrication Parts.

Filled or Masking Region
Added the ability to draw filled regions in 3D families.

Floor
Added the ability to show the Height Offset from Level in floor and foundation slab tags.
Improved the performance ranging from 20% to 90% based on the operation and the number of control points on the floor, previously it took 21 seconds to select a floor with 10k points, now it takes 7 seconds.
Added flexible visual control for Floor Interior Folding Lines and Split Lines.
Improved the pattern orientation when mirroring the floor.

FormIt Converter
Added the ability to launch FormIt from Revit to edit the selected linked FormIt model in one click.
Added the ability to link FormIt files via the API method Document.Link.
Fixed an issue where silhouette edges would not draw on curved surfaces originating from FormIt.

Foundation
Added the ability to choose if a Structural Foundation family is displayed in a plan view using a specified cut plane in the plan view of the family.

Graphics
Improved the error drawing contents dialog and added a help link.
Improved view performance by an average of 200% in 3D views with selected families containing imported geometry, depending on their complexity.
Improved performance by an average of 25% for some MEP views.
Improved performance by an average of 35% for views with Hidden Lines set to All or By Category to display dashed elements below or beyond.
Improved performance by removing unneeded screen refreshes occurring when the Navigation bar was on the screen resulting in a 25% improvement in views that displayed random redraw behaviors in past releases.
Allowed for nearly instantaneous zooming in view in some views containing spline curves, especially imported ones.
Fixed an issue where the Foreground pattern of a non-masking Filled Region in front of solid masking Filled Region would not display on screen but would Print correctly.

IFC
Combined the Export to IFC As and IFC Predefined Type built-in parameters into one dialog and made them read-only.
Improved the position of certain beams when exporting to IFC.
Added time zone information to the header of exported IFC files, that can be seen in IFC viewers.
Removed restrictions of file size when importing and export IFC files.
Corrected the IFC GUID parameter value on export if the value used was different than the value set for the element.
Improved performance when opening some IFC files that have many grouped elements.
Added the ability to override the names of schedules when using them to create IFC property sets. Removed hidden fields when exporting schedules to IFC property sets.
Improved round-trip of IFC files from Revit that are intended for use in Solibri.
Preserved color when exporting some walls to IFC4 Reference View.
Provided basic support for linking IFC 4.X files, covering the geometries that Revit natively supports.
Improved creation of stable IFC GUIDs for IFC common property sets on export.
Improved IFC export of Revit properties that reference named Revit elements, so that the value shown in the UI is always used.
Added support for exporting combined parameters to IFC when the Export Schedules as Property Sets option is enabled.
Improved saving of options in IFC export configurations.
Improved support for linking in IFC 4 files using the IfcIndexedPolyCurve entity.
Improved some volume calculations when exporting quantities to IFC, and improved storage of some IFC GUIDs when exporting to IFC using the option to store GUIDs on export.
Improved stability while exporting to IFC.
Added support for importing and exporting IFC files of any size.
Added partial support for linking IFC4.X files.

Import from Inventor
Changed the behavior of names for Revit objects created by Inventor to always use the latest name from Inventor.
Enhanced the ability for Revit to read individual surfaces from Inventor.

Import/Export Image
Improved image link and import to allow files with .tiff as well as .tif file extension.
Improved the display and stability of views with Imported and linked raster images that are rotated off 90 degrees, and/or contain transparency while improving performance by 300% for most actions in these views.

Import/Export Other
Improved the appearance of newly imported meshes by hiding internal edges in more circumstances.

Import/Export/Link SAT/SKP
Added import placement controls for the Import CAD formats that didn't previously have these controls (Rhino, OBJ, SAT, and STL).
Improved the ability to import some solids with inaccurate edge information as solids instead of meshes.

Import/Export/Link STL
Added the ability to link OBJ and STL files via the Import CAD command.
Added the ability to Export OBJ files via the existing Export CAD formats tool.

Import/Link DWG/DXF/DGN
Added the ability to host import symbols to named horizontal reference planes.
Added the ability to apply 'Enable cutting in views' for imported symbols created from all kinds of imported and linked CAD formats.

Import/Link Rhino
Improved support for Linked Rhino, OBJ, and STL files in BIM 360.

Install
Adjusted custom install to enable a custom Revit.ini to be stored within the install image at time of creation.

Licensing
Improved an error message when encountering a license error and added a help link.
Improved the UI and behavior in the About Revit dialog.

Location
Weather stations are now enabled in the Location dialog based on the user being logged in with a subscription-enabled account.

MEP Analytical Systems
Integrated the latest EnergyPlus 9.6 to improve systems analysis performance up to 45% in some sizing simulation.

MEP Connectors
Added the ability to rehost a MEP connector on a face or work plane while working in Family Editor.

MEP Fabrication
Reduced the amount of unwanted lateral movement of connected main run elements when moving non perpendicular branch parts.
Added support for in-canvas elevation controls on MEP Fabrication parts.
Improved the behavior of the Change Size feature to prevent changes from rolling back in the event of errors.
Added support for the in-canvas flip controls on MEP Fabrication parts.
Improved the position of the in-canvas annotations.
Improved the name of the following parameters, FABRICATION_PRIMARY_SIZE, FABRICATION_SECONDARY_SIZE, and FABRICATION_BRANCH_SIZE.
Improved the display for self-dimensions so they consistently display relative to the view and view scale.
Improved the in-canvas rotation controls to flex rotated elbows and inline tees to be perpendicular in plan view.
Improved sloped pipe so that branches rolled at 45 degrees are flexed to be perpendicular to the main.

MEP Miscellaneous
Updated some existing families to the new category Plumbing Equipment and relocated the files to the corresponding plumbing equipment directory.
Fixed an issue with nested generic annotation orientation not showing correctly when family instance placed on sloped host.
Fixed an issue with nested generic annotation oriented inconsistently in floor plan and ceiling plan views when hosted on vertical and horizontal surfaces.
Added two new categories "Mechanical Control Devices" and "Plumbing Equipment" nd their tag categories; added corresponding command buttons to the System tab.

Materials
Added support for material textures and decals images cloud path through the Autodesk Docs and Desktop Connector. Material Textures and decal images can be saved as an external server path as Autodesk Docs://... Batch downloading image resource files are supported if files are not available to local disc Desktop Connector mapping folder yet.
Added an option to duplicate a material and its assets at the same time​​.

Opening
Improved the behavior of Phasing InFill to stay the same regardless of the project/cut line weight setting.

Options Dialog
Implemented improved message and added a help link to an error message when opening the default family template file locations.
Improved the Audit Warning in local file opening to remember the user's choice not to show the warning again.

Parameters
Added the Parameters Service to manage and import shared parameters from your Autodesk Construction Cloud account.
Introduced 'fill pattern' parameter type that can be used to control filled region pattern in families.
Added Life Safety to the selection of Property palette groups.
Assigned ForgeTypeId identifiers to include a parameter element's unique ID to ensure uniqueness within a model.
Deprecated the "Visible" property in class ExternalDefinitionCreationOptions.
Provided common parameters for Model Groups and RVT Link.
Improved reporting of parameters when filtered to correctly display Type vs. Instance, and ignore shared parameters loaded from families when duplicated in the model.

Phasing
Changed the behavior of MEP elements after they are demolished to stay connected and maintain their system assignment.

Pipe
Made Reference Level a schedulable parameter for elements under categories Pipe, Pipe Placeholders, Duct, Duct Placeholders, Cable Tray, and Conduit.
Added built-in type parameter Elevation Base that enables the tags' elevation values to be calculated to different references to Pipe Tags, Duct Tags, Cable Tray Tags, Conduit Tags, MEP Fabrication Pipework Tags, MEP Fabrication Ductwork Tags, and MEP Fabrication Containment Tags.
Updated the Properties palette with new elevation parameters for elements under the categories Pipe, Duct, Cable Tray, Conduit, MEP Fabrication Pipework, MEP Fabrication Ductwork, and MEP Fabrication Containment.
Updated the list of elevation parameters for tags, schedules, and Properties palette of elements under the categories Pipe, Duct, Conduit, Cable Tray, Conduit, MEP Fabrication Pipework, MEP Fabrication Ductwork, and MEP Fabrication Containment; updated existing families containing obsoleted elevation parameters in the content library with updated elevation parameters.

Precast
Added the ability to load the Precast families without opening the Configuration menu.

Print
Added the ability to use the view/sheet set dialog in the Print feature to customize page order, naming convention, and other options.
Improved vector printing to handle transparent fills added to ducts and pipes that did not print previously in some views.
Improved print and export performance by up to 40% through the addition of parallel processing.
Improved printing so detail elements that are in linked models do not incorrectly create hidden lines in the host model.
Improved printing so that Hidden Lines created by linked models with multiple instances in the view display and print correctly.
Improved printing for views with Hidden Lines set to all so that Hidden Lines created by linked models below model elements in the host print as displayed on screen.
Improved printing so that Color Fills with a line pattern assigned do not overlap cut lines of walls and hosts in plan views.

Project Browser
Added an icon to the Project Browser that indicates the sheet placement status of views and split schedules.

Ramp
Provided the ability to copy a Spot Slope annotation from a floor to a ramp.

Reinforcement
Added the ability to copy and adapt free form rebar between concrete hosts, by matching their rebar constraints.
Added the ability to show the rebar cover parameters in schedules and tags, for all structural elements that can host reinforcement.
Improved the performance when zooming or panning in a view with lots rebar.
Improved the performance when selecting many rebar in complex hosts, 2D views.
Added the ability to toggle visibility for the entire set, when selecting one bar in the rebar set.
Rebar can now constrain to faces resulting from joins between the host and other elements.
Added the ability to copy and adapt free form rebar between concrete hosts, by matching their rebar constraints.
Updated the rebar shapes in the UK library according to the latest standard.
Added the ability to set the unobscured property of rebar elements for multiple views, inside the View Visibility States menu.
Fixed an issue where the work plane was incorrectly set when sketching a single segment free form rebar.
Added the ability to assign a shortcut key to the Toggle Visibility command available in the right-click menu for reinforcement elements.
Added the ability to toggle between obscured and unobscured for Rebar Couplers, Fabric Sheets, and Area and Path Reinforcement by using the Toggle Visibility command in the right-click menu.
Added the ability to search by view name inside the View Visibility States for rebar elements.
Improved the behavior of rebar to always show as solid in 3D views set to fine.
Improved the display of the rebar placement tooltip to avoid flickering when moving the cursor.
Improved the placement of the bar handle controls and options when editing rebar constraints on all resolutions and DPI scaling settings.
Added the ability to copy and adapt shape driven rebar between concrete hosts, by matching their rebar constraints.
Added the ability to show rebar as solid in 3D views of linked Revit models.
Improved the performance in BIM Collaborate / Autodesk Docs Viewer, by up to 5x, when publishing a 3D view of the full rebar model and, on average by up to 30x, when opening the same view, for medium to large building models with 4000+ rebar.
Added the ability to rotate rebar couplers and choose if the coupler geometry is aligned to the view or to the connected bar in 2D views.
Improved the behavior of Create Similar to select the last tool used for rebar placement.
Added the ability to select bars in a varying rebar set from a rebar schedule.
Added the ability to inspect the parameter values of individual bars in varying rebar sets.

Revit Cloud Model (workshared)
Improved the wording for a cloud collaboration error message and added a help link.
Improved wording for an error message regarding cloud worksharing communication.
Enabled Autodesk Docs and BIM 360 Docs accounts last used to be remembered in the Save as Cloud Model dialog.
Implemented a non-destructive way of rolling back to previous versions of a Revit Cloud Workshared model available in Revit Home
Consolidated the Manage Cloud Models dialog functionality (publishing, rollback and force relinquish) in Revit Home

Schedules
Improved schedules to show only elements visible on sheet.
Added the ability for Room and Area category key schedules to be preserved on the element, when disassociating a key from an element (setting it back to none) the current parameter values, which are then modifiable as needed.
Added the ability to do conditional formatting per Family and Type, Family, and Type in schedules.
Fixed the incorrect information update in combined parameters of schedules.

Section/Elevation
Improved performance when selecting or editing a complex sketch element, such as a floor containing large number of boundaries. Previously, it took 47 seconds for the Edit Boundary command to complete, now it takes 17 seconds.
Improved the performance when there is large amount of redundant rooms in the Revit file. For example, loading a linked model to the host model, which contains over 3,000 redundant rooms, previously it took 65 minutes, now it only takes 12 minutes.
Improved the performance when there is large number of items in the Type Selector drop-down list. For example, in a model containing a large number of detail items, previously it took 48 seconds to populate the Type Selector dropdown list, now it displays immediately.

Selection
Exposed to the API the methods Autodesk.Revit.UI.Selection.SetReferences() and Autodesk.Revit.UI.Selection.GetReferences() allowing an application to select a Revit reference and retrieve selected Revit references.
Exposed to the API the event Autodesk.Revit.UI.UIApplication.SelectionChanged.
Added ability for the customer to toggle off onscreen icons using Activate Controls to remove screen clutter and improve view performance by up to 750% for views with large numbers of controls such as pins and curtain wall panel type constraints.
Improved performance in all views with large numbers of elements selected by an average of 200% when a large number of onscreen controls such as pins are displayed.

Sheets
Added new APIs for understanding the view transforms from 3D model space to view projection space to sheet space.
Added the ability to swap a sheet viewport to any other compatible view in the model, using either the viewport center or view origin as the positioning method.

Site
Improved the performance of Slab Shape Editor when selecting and editing multiple points.
Improved the Contour Label Orientation to easier read mode.

Sketching
Improved performance of operations that involve creation of many sketch based elements such as copying many floors or roofs at the same time. Previously copying 1024 to make 2048 floors, takes 5 minutes and 24 seconds, now it only takes 58 seconds.
Added a snippet missing from SketchEditScope API documentation.
Extended Document.NewDimension methods to support creation of dimensions in Sketch edit mode.
Added a new Element.IsModifiable read-only property to the public API.

Slab
Improved the performance by 60% when doing operations on slab shape editor, previously it took 1.5s to select two floors each with 10k control points, now it takes 0.5s.

Snapping
Improved the UI and interaction behaviors for measure in 3D views.
Enabled the Measure tool in 3D views.

Steel Connections
Added the ability to change the properties of structural steel connections implemented based on .NET API using Modify Parameters from Edit Type and from Override by Instance.
Improved behavior of the value of the shared parameter assigned to a steel sub-element of a steel connection so that it is kept after breaking the steel connection.

Steel Connections for Dynamo
Fixed a localization issue for German installation with the Steel Connection Automation script reporting.
Improved steel connection automation sample scripts by removing the custom nodes dependency and increasing the visibility on filtering elements nodes.
Added documentation URL to Revit Help pages to out-of-the-box connection automation scripts.
Added descriptions to steel connection automation sample scripts.
Updated the icon and button name that launches Dynamo Player with Steel Connection Automation sample scripts, from the Structural and Steel tabs.
Improved steel connection automation sample scripts by clarifying the way beam slope parameter acts for different beam to column web or flange situations.
Enhanced the Steel Connection Automation functionality by providing a new workflow – Library Based Connections Design Automation, that uses a newly added steel connection library with a relevant sample of steel connections defined by AISC, BCSA and DsTV standards
Added the sorting ability for the imperial format values, the ability to filter strings containing spaces, and input multiple connection families within the steel connection automation sample scripts.
Improved connection ranges of applicability API with property constructor that has implicit units.

Steel Fabrication Beam
Added thickness information to the steel plate elements inside the IFC export.

Sun Path
Enhanced drag-and-drop operations with real-time visual feedback in Multi-day Sun/Path editor.
Enhanced drag-and-drop operations with real-time visual feedback, in Single day Sun/Path editor.
Enhanced the drag-and-drop operations with real-time visual feedback in the Still Sun/Path editor.

Sun and Shadow
Added solar study editor commands to set options for sun and the shadows from the ribbon.
Added interactive geographical location options for solar study editor.
Added interactive study preset option for solar study editor.
Added interactive study type option for solar study editor.
Added interactive date options for solar study editor.
Added interactive time options for solar study editor.
Added an interactive time interval option for solar study editor.
Added relevant information about solar study simulation state in the Revit's status bar, for consistency with other workflows.
Enhanced the solar study editor to perform with time-based animation, model navigation, and ribbon controls.
Enhanced the solar study editor to perform simulation with interactive options and added visual feedback for sun/path editing operations.
Enhanced the solar study editor to perform simulation with time-based animation and added the ability to navigate the model during simulation.

Tags
Made multi-leader tag parameters easier to find in the edit label dialog by showing all available parameters by default.
Added the ability to displace any element in 2D views and tag displaced elements in 2D and 3D views.
Added support for tagging capability for Arches, Cross Bracing, Diaphragms, Girders, Trusses, and Vibration Management.
Enabled tagging for Model Groups and RVT Links.
Enabled tagging for more categories: Columns(Architecture), Entourage, Fascias, Gutters, Roof Soffits, Handrails, Pads, Ramps, Slab Edges, Top Rails, Wall Sweeps, Model Group, and RVT Links.
Added the ability to tag individual bars in rebar sets and control the visibility of the tag leaders.

Units
Added digit grouping type, "123 456 789.00".

User Interface
Removed the redundant Insulation width setting from the option bar so that all related settings are now in the Property palette.

View
Added the detail number and sheet number to the viewport view list, making it possible to identify which view is already placed on a sheet.
Added search functionality to the View Reference command, for the View Type and Target View parameters.
Improved the performance when overriding the graphics on a small portion of elements, previously it took 12 seconds to update the elements or category's graphics, now it takes 6 seconds.
Improved performance of navigation in all views by an average of 35% through optimization of thumbnail creation used by the Rewind tool.
Improved the performance when dragging an annotation or editing parameters in the Revit model containing large number of view filters. For example: in a Revit model with 350 view filters, previously it took 160 seconds to drag a pipe tag, now it takes 2 seconds.

View Filters
Added the ability to filter Wall Sweep and Roof Soffits in View Filter.

Wall
Provided an error message to indicate corrupted elements.
Added the ability to set the structural usage for structural walls to Non-bearing.
Added the ability to set the structural usage for structural walls to Non-bearing.
Improved the automatic geometry join behaviors between stacked walls and floor when they overlap.
Provided the ability to filter walls in a view by: Base Constraint, Base Offset, Top Constraint, Top Offset.

Workplane
Added separated command as quick access to enable “Pick a Plane” option in the existing set Work Plane Dialog.