Autocad Fatal Error Acismobj20dbx Best

Navigate to your AutoCAD installation folder. Typically: C:\Program Files\Autodesk\AutoCAD 20xx\

Search for acismobj20dbx.dbx. Note the exact path.

Sometimes, the error is not AutoCAD's fault—it's the drawing file. One 3D solid in your drawing has a "poisoned" ACIS history. autocad fatal error acismobj20dbx best

If you cannot open the drawing at all:

If you can open the drawing but it crashes on a specific action: Navigate to your AutoCAD installation folder

Pro Tip: Use _EXPLODE on suspect 3D solids to convert them to 3D faces, then re-extrude. This breaks the ACIS corrupt chain.


Several factors can lead to the "Autocad Fatal Error Acismobj20dbx": If you can open the drawing but it

If all else fails, you need a surgical reinstall. But do not simply uninstall from Control Panel—that leaves behind the problematic acismobj20dbx registry keys.

The "Best" Uninstall Protocol:

  • Registry Clean: Press Win + R, type regedit, navigate to HKEY_CURRENT_USER\Software\Autodesk and HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk. Delete the keys for your specific AutoCAD version.
  • Reboot and reinstall.
  • Alternative: Instead of a clean reinstall, perform an In-Place Upgrade (install the same version over itself). Autodesk's installer will detect missing or corrupt .dbx files and replace them without losing your custom settings. This is often the best middle-ground solution.