Some users may experience issues in Blackboard Collaborate, such as being unable to connect, not being heard by others, or others not being able to hear them.
If you experience these issues, or an issue similar to them, we recommend using Google Chrome as your web browser, at least when you're using Blackboard Collaborate. Blackboard Collaborate was initially designed to be commonly used by Google Chrome, and is still maintained with the assumption that most users would be using Google Chrome.
You can also refer to our support article on clearing your browser cache. You can try clearing your browser cache for the web browser you're using, before giving Google Chrome a try.