Meeting for a Community Unaccessible

Hello,

We have a large community meeting that is inaccessible to people trying to join. We get the attached message when people are attempting to, the message is 'The Host has Another Meeting in Progress' and a circular bar that keeps going round and round. Is there some kind of setting on our meeting that is making it impossible for some people to join that we need to change? Does anyone know under what circumstances people get this message and what the host needs to do to let them enter--- preferably automatically also instead of having to let everyone in manually. Thank you for your help!

Jon