Well, the program tries to create (update) the cache-file, you can find under "\Data\FileCache.dat".
That file contains the list of your programs and other files.
It is used to speed up and improve the procedure of fixing found registry problems (e.g. by the registry cleaner).
You can remove that file, but RegSupreme Pro will always recreate it.
So, be patient and let the program create (update) that cache-file. That can take several (up to 20) minutes ...