Host has blocked meeting

I am not aware of any message that says “Host has blocked access”. However, it is possible that the host may have LOCKED the meeting accidentally, especially if these two participants were last to join.

It may have been that the host accidentally locked the room.  When this feature is enabled, new participants cannot join the meeting even if they have the invite link, and they may notice something like "Unable to join this meeting. Host has locked the meeting."  Only the host can unlock the room. It is best to enable the waiting room feature. This way, only the host can let people into a meeting.  When scheduling meetings ensure that the lock feature is off. Hope this helps.