Issue:
Drawing files in AutoCAD products end up being much larger than they should, often with no obvious data in them. Other symptoms include:
- Failure to copy and paste elements.
- Hanging for a long time when selecting text with the Properties palette open.
- Drawing file takes a long time to open.
Causes:
- Corrupt data in the drawing.
- The DWG was created in a non-AutoCAD application.
- Many AEC objects or metadata in the file.
- Drawing contains a large number of annotation scales.
- Unmapped DGN Linetypes
Solution:
Try one or more of the following:
File repair and maintenance
- Clean the AutoCAD drawing with the Autodesk Drawing Cleanup Utility, see Autodesk Drawing Cleanup Utility for AutoCAD Tool Guide
- Repair corrupt drawings. See How to repair corrupt AutoCAD files.
- Optimize the drawing:
- Optimizing the AutoCAD drawing file: Purge, Audit & Recover (note: check the box for "Automatically purge orphaned data").
- Optimizing the AutoCAD drawing file: Windows Clipboard Copy and Paste.
- If drawing is expected to contain only AutoCAD geometry and annotation object purge the AEC object data using PURGEAECDATA (Command); alternatively export the drawing to AutoCAD EXPORTTOAUTOCAD (Command).
- Reduce the number of annotation scales in the drawing file; see Warning: "This drawing contains a large number of annotation scales" when opening a file in AutoCAD Products.
- Use the RegApp Cleanup utility to remove RegApps from multiple files (host and Xref drawings); see How to install the Regapp ID Cleanup Utility for AutoCAD.
- Reduce the number of Viewbase Drawing views in any one layout or attach the views as an external reference. See About Attaching and Detaching Referenced Drawings (Xrefs).
- Export then reimport the file using:
- The DXFOUT and DXFIN commands.
- The DGNEXPORT (select V8 DGN format) and DGNIMPORT.
- Clean DGN linetypes from the drawing. See How to clean DWG files from the extra DGN linetypes with AutoCAD 2015 or greater.
Presence of a large number of empty voltage definitions (from MEP's Electrical Preferences):
If the drawing database contains a large number of empty voltage definitions, it can significantly increase file size and impact performance. To address this, follow the steps below:
- Open the affected drawing in AutoCAD or any of its verticals.
- Copy all objects and paste them back into the same drawing to trigger the cleanup logic in AecbElecBase.dbx.
- Allow the process to complete; the application may temporarily freeze due to the volume of entries.
Please note, the paste process may take several hours depending on the file content and the number of empty voltage definitions.
Optional: To verify the cleanup, open the drawing in AutoCAD MEP and run the ELECTRICALPREFERENCES command. Check the Voltage Definitions tab to confirm the duplicates are cleared. (Avoid opening this tab before cleanup, as it may cause the application to freeze.)
Update applications
- Install the latest AutoCAD updates. See Where to download software and updates | Individuals | Autodesk Support.
- Uninstall older versions of DWG TrueView and install the version matching the currently installed AutoCAD release.
For Autodesk Civil 3D
- Run the command AECCPURGEACANODOBJECTS.
- Run the "defaultClean" script in Autodesk Batch Save Utility.
- See How to fix Civil 3D Drawings.