d3d9caps64.dat is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like d3d9caps64.dat, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like accicons.exe - to follow. These files were created so that multiple programs (eg. Office) could share the same d3d9caps64.dat 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 DAT 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 d3d9caps64.dat is attempted to be loaded either when Office is starting up, or in some cases already running. Some of the most common d3d9caps64.dat errors include:
- Access Violation at address - d3d9caps64.dat.
- d3d9caps64.dat could not be found.
- Cannot find C:\Users\Bill\AppData\Local\d3d9caps64.dat.
- Cannot register d3d9caps64.dat.
- Cannot start Office. A required component is missing: d3d9caps64.dat. Please install Office again.
- Failed to load d3d9caps64.dat.
- The application has failed to start because d3d9caps64.dat was not found.
- The file d3d9caps64.dat is missing or corrupt.
- This application failed to start because d3d9caps64.dat was not found. Re-installing the application may fix this problem.
Your d3d9caps64.dat file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with Office), or deleted by a malware infection. Furthermore, d3d9caps64.dat file corruption could be caused from a power outage when loading Office, system crash while loading d3d9caps64.dat, 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.