Check to see if Flash is installed. Follow this link and follow the instructions to check Flash -
You may also need to check the settings in your browser to make sure that Flash is active.
Make sure your Flash settings are to “Allow” and “Remember” Collaborate’s access to your camera and mic
If you don't have a mic installed, or it's been disabled due to security, you may see this message -->
Click the almost-invisible X in the upper right corner to click past the message and continue to join the session.
If you can join the session on your computer, but don't have a mic installed, you can still phone into the session using the "Session Menu" in the upper left of the session, and clicking on "Use your phone for audio."
You will be given a phone number to call and unique pin that will that attach your phone to your computer Ultra session identity.