Join meeting failed with error code 100000400

Hi, team
Sometimes, I join meeting failed with error code 100000400. Why failed? How to fix it?

I got this too, this morning, trying to connect ZoomOSC to a Webinar with Backstage. ZoomOSC was authenticated with my main account, already logged into the Webinar.
The webinar was not yet started. Once I started the webinar from Backstage, the Join worked.

@yanfuyong20121, I’m guessing that’s what’s happening in your case… you’re joining a webinar that hasn’t yet been started.

Note: When ZoomOSC was able to join, it joined the Webinar in Backstage – not as an attendee. Further, it joined with Co-Host privilege and presented the “Reclaim Host” button… so ZoomOSC and the Zoom server knew I was supposed to be authorized to join.