Every so often your internet browser will update or have setting configuration changes related to how flash content displays. This can break the functionality so that when you try to 'join' Adobe Connect sessions you get a frozen loading bar or just a blank white screen.
Assuming that you are using your laptop the meets the Harrisburg University Laptop Requirements (https://helpx.adobe.com/adobe-connect/connect-support.html) then you may need to work with Adobe's support via chat. They are very prompt and helpful. Just tell them that you can't access any room.
Once you open the link click on the chat icon in the lower right hand corner: