Some users will attempt to join a Blackboard Collaborate session but get stuck at the loading animation. This occurs when third-party cookies are not enabled in their web browser. This should be resolved simply by enabling the third-party cookies.
Blackboard documentation link: https://blackboard.secure.force.com/publickbarticleview?id=kA7390000004FQK If you need any assistance with enabling third-party cookies, please feel free to reach out to the Tech Support team at 515-965-7300 for assistance