Hi mgcnc,
System File Checker gives an administrator the ability to scan all protected files to verify their versions. If System File Checker discovers that a protected file has been overwritten, it retrieves the correct version of the file from the cache folder (%Systemroot%\System32\Dllcache) or the Windows installation source files, and then replaces the incorrect file. System File Checker also checks and repopulates the cache folder."..."If the cache folder becomes damaged or unusable, you can use the sfc /scannow, the sfc /scanonce, or thesfc /scanboot commands to repair its contents.
Use the following link for instructions to Use sfc /scannow to Fix Windows System Files.
I suspect this will resolve the issue. If you require further assistance let me know, but include some additional information in your post, such as, your operating system, when this message appears, and what the full error says. Knowing the full error might help me identify what file is missing.
Hope this helps.