Can you try running RegEdit (Registry Editor) and removing all entries with “MCEBuddy”? Not sure if you had BCUninstaller do this extra step or not.
Then try installing a fresh trial version.
Worst case, you can always go back to re-install the latest 2.5.7 version 04/18/2022, before the premium subscription change. You indicated you were using a 2.5.x version in another thread.