Zoom Meeting ID Error Code: Works for some but not others

[Zoomstroller]

I host various meetings on ZOOM and on occasion, I notice that some members are reporting that the ZOOM meeting number is reporting it is invalid or an error code is sent.  Why does the link work for the majority but not for all?  How can I troubleshoot this issue?  One member had just created a ZOOM account prior to the meeting and could have delayed their access, but others are existing members.