BitDefender is a very troublesome antivirus that can be described as a trigger-happy cowboy. There have even been reports of it blocking critical Windows 10 files that Windows relies on to run smoothly.
BitDefender has also blocked WeMod for some users before even though they added it as an exception. Check your quarantine menu in BitDefender for any WeMod files stuck in there.
I’d recommend switching to a different antivirus. A free one is just as good as a premium one, as long as you’re smart and don’t click unknown links on the internet.
But if you’d rather keep BitDefender, you’ll need to do some tweaking: How to white-list WeMod in BitDefender!