Sometimes the error is tied to a corrupted user profile. Navigate to the Windows Start menu, find the AutoCAD 2021 folder, and select Reset Settings to Default
. Note that this will wipe custom toolbars and command aliases. Clean Reinstall problem loading acadresdll resource file autocad 2021
Ensure your operating system is fully updated, specifically regarding .NET Framework updates which AutoCAD utilizes. Sometimes the error is tied to a corrupted user profile