Do not uninstall yet. Resetting the user profile clears any corrupted registry pointers to acismobj20dbx .

If you are a CAD professional, architect, or engineer, nothing kills productivity faster than a sudden crash. You are in the middle of a complex 3D modeling session, and suddenly, the dreaded message appears:

Now re-register it:

autocad fatal error acismobj20dbx best , acismobj20dbx , register dbx autocad , ACIS fatal error fix .

Or simply:

Published by: CAD Troubleshooting Desk Target Keyword: autocad fatal error acismobj20dbx best Difficulty Level: Intermediate to Advanced

This specific error is particularly notorious because it directly points to the —the core component that handles 3D solids, surfaces, and regions. When the acismobj20dbx (ObjectDBX wrapper for ACIS) file becomes corrupt, mismatched, or conflicts with another module, AutoCAD will terminate immediately.

Search for acismobj20dbx.dbx . Note the exact path. In the Administrator Command Prompt, type the following (adjust the path to your version):


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