Issue: Civil 3D initially opens tutorial drawings fine, but after one hang event, the Recent Documents list clears and now any file — even the ones that worked — causes a freeze.
Cause: Civil 3D caches file history and drawing thumbnails in a local roaming profile folder. When a crash corrupts these caches, Civil 3D can’t read them and loops endlessly trying to regenerate previews on startup.
Solution:
Step 1: Reset Thumbnail Cache – Navigate to %LOCALAPPDATA%\Autodesk\C3D <version>\enu\Support\Recent File List and delete the XML/thumbnail cache files.
Step 2: Disable Start Tab Preview – Type STARTMODE and set it to 0 to bypass the recent list temporarily.
Step 3: Open from Command Line – Launch Civil 3D, type OPEN at the command line, and manually select a known-good DWG (ideally local).
Step 4: Rebuild User Profile – If the issue persists, use Civil 3D’s built-in RESET SETTINGS TO DEFAULT tool to rebuild the entire user profile and clear any broken registry keys.
Step 5: Reconnect Shortcuts & Templates – Once Civil 3D is stable, re-add your support paths, tool palettes, and templates from the network.
This problem feels random when it happens — but it’s usually fixable in under 10 minutes once you know where Civil 3D hides its file history.
