Adobe Connect: I have a user that cannot connect to a meeting room

The user clicks on the meeting room link and keeps getting a "This page cannot be displayed..." with notes about checking his internet connection. His connection is fine and he is only getting this message from Adobe Connect meeting rooms. I sent him the meeting connection diagnostic test. He saw all the verbiage from "Meeting Connection Diagnostic" down, but not the actual test results above. This user works for a law firm and we think that it might be security settings not allowing him to access this site. I looked on the web, but couldn't find a similar issue in my search. Does anyone have any experience with this or advice. Thank you in advance.

Thanks,

Brian