AcAuthEntities23enu.tlb is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like AcAuthEntities23enu.tlb, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like ADPClientService.exe - to follow. These files were created so that multiple programs (eg. AutoCAD) could share the same AcAuthEntities23enu.tlb file, saving valuable memory allocation, therefore making your computer run more efficiently.
Unfortunately, what makes DLL files so convenient and efficient, also makes them extremely vulnerable to problems. If something happens to a shared TLB file, either it goes missing or gets corrupted in some way, it can generate a "runtime" error message. Runtime is pretty self-explanatory; it means that these errors are triggered when AcAuthEntities23enu.tlb is attempted to be loaded either when AutoCAD is starting up, or in some cases already running. Some of the most common AcAuthEntities23enu.tlb errors include:
- Access Violation at address - AcAuthEntities23enu.tlb.
- AcAuthEntities23enu.tlb could not be found.
- Cannot find C:\Autodesk\WI\Autodesk AutoCAD 2020\x64\acad\PF\CF\AdShared\AcAuthEntities23enu.tlb.
- Cannot register AcAuthEntities23enu.tlb.
- Cannot start AutoCAD. A required component is missing: AcAuthEntities23enu.tlb. Please install AutoCAD again.
- Failed to load AcAuthEntities23enu.tlb.
- The application has failed to start because AcAuthEntities23enu.tlb was not found.
- The file AcAuthEntities23enu.tlb is missing or corrupt.
- This application failed to start because AcAuthEntities23enu.tlb was not found. Re-installing the application may fix this problem.
Your AcAuthEntities23enu.tlb file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with AutoCAD), or deleted by a malware infection. Furthermore, AcAuthEntities23enu.tlb file corruption could be caused from a power outage when loading AutoCAD, system crash while loading AcAuthEntities23enu.tlb, bad sectors on your storage media (usually your primary hard drive), or quite commonly, a malware infection. Thus, it's critical to make sure your anti-virus is kept up-to-date and scanning regularly.