There could be several reasons for this.
- If you are trying to join a meeting which is not starting in 15 minutes, you may be unable to connect to the meeting. Most meeting links work 10-15 minutes before the Meeting Start Time.
- You are using the wrong URL or Meeting ID to join the meeting.
- You are not connected to the Internet.
- You are not part of the existing meeting. Meetings are sometimes by invitation only.