Hello juene240,
Thanks for that info and for choosing the Apple Support Communities. If we understand correctly, you are unable to use a 3rd party video conferencing software on your Mac. You can figure out if unexpected behavior is related to a user file or setting by trying to reproduce the issue from another user account. This process includes creating a new user account, logging in to it, and testing for the issue.
Set up users, guests, and groups on Mac
Next, contact Blackboard support for more help with their software system:
Blackboard Collaborate | Blackboard Help
How to contact an app developer
Contact a third-party vendor
Cheers!