DLL cache corruption

Occasionally people get crashes on startup because a cached relinked DLL got corrupted. This should be investigated.
Possible partial fixes:
- If a cached DLL fails to load, delete it so Everest won't attempt to load it again on next startup.
- The same, but load the actual DLL on the same run (not sure if this is viable, since there's a chance the broken DLL is already partially loaded).