Only follow these instructions if you are having issues after having un-subbed/deleted FFHRRM.

Go to your Left 4 Dead 2 directory by right clicking Left 4 Dead 2 in your library and selecting Properties > Local Files > Browse Local Files

From there proceed through folders Left 4 Dead 2 > cfg and find the "config.cfg" file.

Open it with Notepad and select all the text. Delete it, then save the file.

Run Left 4 Dead 2 to force it to re-generate the contents of the config.cfg file, hopefully solving any issues you may have been having.

However, do note that by doing this all your key-binds and several other settings will be either reset to defaults or completely unbound.

You will need to change these options again to your preference.

If you are still having issues after attempting this fix make sure to leave a reply to this discussion, and ill do my best to help you.