While in zoom meetings...

1) I am Host, and I want to share my presentation. Atendee/ Invitee cannot see it in her screen.

2) When atendee/ invitee wants to share her presentation, an error message pops out, reading "it is not possible to share screens. Try again later. "Error code: 0".

What do I do, just so atendee/ invite can see my presentation and she can share hers?

A client that uses Zoom regularly keeps trying to send me invites to Zoom meetings but these invites are not coming through to my Gmail address at all. I have checked Spam and Promotions tabs and have done a global search in Gmail for the no-reply@zoom.us address -- with no luck. The client is not receiving any error messages on their end and I have been unable to find anything here in the Community or in Zoom Support or across all of Google to help solve this problem. Any help will be greatly appreciated because this situation is getting VERY frustrating for me and for the client. Thank you!

I created polls to use on meeting.
It worked well before the meeting but during the meeting, it didn't work with this message. ->
"You are logged in from another device. Your polling session is inactivated." (the message was in Korean, so I translated. It is not accurate in English).

After the meeting, I tried again the meeting and the polling system works well.
What is the problem?
While I conducting meeting, nobody logged with my account.

I attached file that captured image the message.

Thank you.

Can someone help troubleshoot to guide us on how to enable the "join" button to appear when prospects register at https://bit.ly/nltm-rsvp and a recurring meeting series is in progress?  Pre-registrants for another nonprofit with similar Zoom settings and an alias see the "join" button when their meetings are in progress.  The only difference may be to remove the passcode in both the account and meeting settines, which we thought we did given we secure using waiting room because attendees find it hard to remember different links and passcodes as well as may not know or want to log into a Zoom account to bypass authentication.

There are too many settings in Zoom to troubleshoot and test.  Hence, we'd appreciate guidance to resolve this problem efficiently.  

While in zoom meetings...

1) I am Host, and I want to share my presentation. Atendee/ Invitee cannot see it in her screen.

2) When atendee/ invitee wants to share her presentation, an error message pops out, reading "it is not possible to share screens. Try again later. "Error code: 0".

What do I do, just so atendee/ invite can see my presentation and she can share hers?