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