It’s SOLVED!!!
If there’s other users with the same issue I had with Groove Agent SE 5 Expansion, I’d like to say that the solution mentioned in the earlier posts works!! Unfortunately it wasn’t my case! I had to contact Steinberg and do a TeamViewer session with a technician because there was a missing file in my installation (It was NOT a 32/64bit issue as I mentioned!!).
Note: This was a Steinberg bug that they are already trying to fix!
There’s this other one solution that may help in other cases:
Good Luck!!!