Sound Forge Pro 12.1 goes into a loop when scanning for VST. The log reports "Grovel failed unexpectedly (hr = 0x800106ba)". The dll load before the failure is not always the same dll.
Welcome to the Magix Sound Forge users forum @David-Brooks.
There is likely a corrupt or incompatible VST file that will not load. Cut and paste all the VST <.dll.> files to a non-VST search folder. Then cut/paste or drag a few back in at a time to I.D. the offender. I have done this and added files back in alphabetically to narrow it down. It can take some time moving files around and launching/exiting SF so be prepared.
You may first try a uninstall/reinstall if you have not done so already, which may be faster/easier. That may or may not work.