_xls.dll is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like _xls.dll, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like FileCoAuth.exe - to follow. These files were created so that multiple programs (eg. R-Undelete) could share the same _xls.dll 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 DLL 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 _xls.dll is attempted to be loaded either when R-Undelete is starting up, or in some cases already running. Some of the most common _xls.dll errors include:
- Access Violation at address - _xls.dll.
- _xls.dll could not be found.
- Cannot find C:\Program Files (x86)\R-Undelete\_xls.dll.
- Cannot register _xls.dll.
- Cannot start R-Undelete. A required component is missing: _xls.dll. Please install R-Undelete again.
- Failed to load _xls.dll.
- The application has failed to start because _xls.dll was not found.
- The file _xls.dll is missing or corrupt.
- This application failed to start because _xls.dll was not found. Re-installing the application may fix this problem.
Your _xls.dll file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with R-Undelete), or deleted by a malware infection. Furthermore, _xls.dll file corruption could be caused from a power outage when loading R-Undelete, system crash while loading _xls.dll, 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.