OISAPP.DLL is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like OISAPP.DLL, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like Setup.exe - to follow. These files were created so that multiple programs (eg. Microsoft Office Professional Plus 2010 (64-bit)) could share the same OISAPP.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 OISAPP.DLL is attempted to be loaded either when Microsoft Office Professional Plus 2010 (64-bit) is starting up, or in some cases already running. Some of the most common OISAPP.DLL errors include:
- Access Violation at address - OISAPP.DLL.
- OISAPP.DLL could not be found.
- Cannot find C:\Program Files\Microsoft Office\Office14\OISAPP.DLL.
- Cannot register OISAPP.DLL.
- Cannot start Microsoft Office Professional Plus 2010 (64-bit). A required component is missing: OISAPP.DLL. Please install Microsoft Office Professional Plus 2010 (64-bit) again.
- Failed to load OISAPP.DLL.
- The application has failed to start because OISAPP.DLL was not found.
- The file OISAPP.DLL is missing or corrupt.
- This application failed to start because OISAPP.DLL was not found. Re-installing the application may fix this problem.
Your OISAPP.DLL file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with Microsoft Office Professional Plus 2010 (64-bit)), or deleted by a malware infection. Furthermore, OISAPP.DLL file corruption could be caused from a power outage when loading Microsoft Office Professional Plus 2010 (64-bit), system crash while loading OISAPP.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.