Confirmation link not working

[Bblue]

With a meeting I organized and hosted, some of my meeting participants could not access the meeting.  This is what one of them said:

I definitely had issues today. I was registered for the meeting prior to today and even got the email with the meeting link this morning. However when I went to join the meeting it redirected me to register again. I tried several times to join from my computer and phone but it still requested me to register for the meeting again. 

[Rupert]

Is this a recurring meeting?

[Bblue]

Hi, yes, it is.

[Rupert]

How do you have your Registration option set? See below.

And did you Edit your meeting or its Recurrence between the affected Participant registering and the meeting taking place?

Could the Participant have registered prior to a prior instance of the Meeting?