Missing Schema Folder

If the schemas folder is missing, empty, or contains damaged files, the Missing Schema Folder dialog displays. Repair/reinstall Revit LT, or replace the folder with the contents of the folder from a working Revit LT installation.

The schema folder contains files related to the processing of units in Revit LT. This folder must be present, and contain valid files in order for Revit LT to start properly. If this folder is missing, contains files not expected, or the files are damaged in some way, you will receive an error dialog and Revit LT will close. You must repair this condition in order to start Revit LT.

You have 3 options; repair/reinstall the Revit LT installation, run the RevitUnitSchemas.msi from the installation media, or copy the files from a workstation where Revit LT is opening correctly to the workstation where Revit LT is not opening.

To repair/reinstall:

1. Launch Windows Control Panel.
2. Select Uninstall a program.
3. Select Revit LT 2026 Release from the list.
4. Select Uninstall/Change.
5. After the install wizard launches, select repair or reinstall.
6. Follow the prompts to repair or reinstall.

Run RevitUnitSchemas.msi:

1. Open Windows File Browser.
2. Navigate to the Revit LT installation media.
3. Perform a search for: RevitUnitSchemas.msi
4. Double Click the RevitUnitSchemas.msi file.
5. When the installer completes, attempt to start Revit LT again.

Replace schema folder:

1. Open a file browser on a workstation with a working installation of Revit LT.
2. Copy the contents of the following location: C:\Program Files\Common Files\Autodesk Shared\Revit LT Schemas 2026 Release, to the same location on the workstation receiving the error.
3. Attempt to start Revit LT again.