The fatal error related to acismobj20.dbx typically occurs when AutoCAD is unable to load or access the file, causing the software to crash. Some common causes of this error include:

. This file is part of the Autodesk Shape Manager (ASM) which handles 3D modeling objects. Primary Cause: Windows Incompatibility

Check your Windows to see if the file was accidentally deleted.

To fix the error permanently, identify the root cause first. Here are the most frequent triggers:

If you are still experiencing crashes after trying these fixes, let me know: What are you currently running?

Your graphics card cannot properly render the ACIS objects handled by this file.