AFAIK the .pdb files that correspond to the dlls are only required when debugging the program in VS. If you don't need to debug the code then just set an exception for the specific pdb file in the VS options. Tools-options-debugging-symbols at least in VS2015, if you get a "no symbols loaded" page with the various links on it, even better.
The "cache symbols in this directory", or something similar perhaps with a different user directory, may hold the .pdb file that you're looking for.
Mine is set to:
c:\users\user\AppData\Local\Temp\SymbolCache and often I find them using the internet search tool in vs15, mostly from MS itself I guess. Anyway right below that there's an option to "Specify excluded modules".
