Host can not register for webinar

I created a webinar using the API (webinarId 91073999662). Then I add participants, panelists and set alternative hosts using the API. To make sure that the list of participants does not intersect with the list of alternative hosts, I set the “alternative_hosts” property to an empty string before adding participants and panelists.

However doing so I still get “code: 3027; msg: Webinar host can not register for the webinar” when I register The webinar host email is

This behavior seems to occur sporadically.

The webinar details is as below:
“agenda”: “”,
“created_at”: “2020-10-23T07:59:11Z”,
“duration”: 55,
“host_email”: “”,
“host_id”: “r5G_yhwYR1e9eSRU0GRT8A”,
“id”: 91073999662,
“join_url”: “”,
“password”: “37744341”,
“registration_url”: “”,
“settings”: {
“allow_multiple_devices”: true,
“alternative_hosts”: “”,
“approval_type”: 0,
“audio”: “both”,
“auto_recording”: “none”,
“close_registration”: false,
“contact_email”: “”,
“contact_name”: “100 CLSA Forum Webinars”,
“enforce_login”: false,
“enforce_login_domains”: “”,
“global_dial_in_countries”: [
“global_dial_in_numbers”: […],
“hd_video”: true,
“host_video”: true,
“meeting_authentication”: false,
“on_demand”: false,
“panelists_video”: true,
“post_webinar_survey”: false,
“practice_session”: true,
“question_answer”: true,
“registrants_confirmation_email”: false,
“registrants_email_notification”: false,
“registrants_restrict_number”: 0,
“request_permission_to_unmute_participants”: false,
“show_share_button”: false
“start_time”: “2020-10-30T12:00:00Z”,
“start_url”: “”,
“timezone”: “Asia/Kolkata”,
“topic”: “The Chinese and American models for big internet companies are both destined to fail”,
“type”: 5,
“uuid”: “WwnJJnSlQaK/j9l/mGpz4g==”

The simplest way to trigger the message is to go to and try to register It should say cannot register host, but the host is and the alternative_hosts field is empty.

Hey @jimmy.tang,

Thanks for reaching out about this—I’m happy to take a closer look.

Can you please share the Add Registrant request URL and Body that you’re passing when you get this error?


Here you go. Thanks!

POST /webinars/91073999662/registrants 
{"first_name": "Sunny", "last_name": "Zhang", "email": "", "org": "CLSA - Americas"}

btw, I’ve opened a case with support as well:

Hey @jimmy.tang,

Thanks for sharing—I can see that the agent working on your support ticket has already opened a ticket with our Engineering team on this, so I will let them continue the conversation with you there.


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