I realize that this is an old thread but I have run into the same problem on a newer machine. I just re-installed BIAB and RealBand on a new computer with Win 10, 16GB of Ram, and an i7 8th generation processor. I get the same error as above of "Counting Candidate Plugins"
I have tried everything mentioned above but to no avail and there wasn't a follow up as to how it was resolved. All the updates to RealBand 2020 are installed but I am at a loss on how to resolve. The computer simply freezes and will not respond and I eventually have to do a restart. BIAB works fine.