lfadst.dat is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like lfadst.dat, 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. YouTube Movie Maker) could share the same lfadst.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 lfadst.dat is attempted to be loaded either when YouTube Movie Maker is starting up, or in some cases already running. Some of the most common lfadst.dat errors include:
- Access Violation at address - lfadst.dat.
- lfadst.dat could not be found.
- Cannot find C:\Program Files\Youtube Movie Maker\skin\lfadst.dat.
- Cannot register lfadst.dat.
- Cannot start YouTube Movie Maker. A required component is missing: lfadst.dat. Please install YouTube Movie Maker again.
- Failed to load lfadst.dat.
- The application has failed to start because lfadst.dat was not found.
- The file lfadst.dat is missing or corrupt.
- This application failed to start because lfadst.dat was not found. Re-installing the application may fix this problem.
Your lfadst.dat file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with YouTube Movie Maker), or deleted by a malware infection. Furthermore, lfadst.dat file corruption could be caused from a power outage when loading YouTube Movie Maker, system crash while loading lfadst.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.