Cannot join meeting that requires registering using the Web SDK

I couldn’t log into a meeting (not webinar) using my hosted Web Meeting SDK because of an error on the installation of “sdk-helper”

Browser Console Error

TypeError: Cannot read properties of null (reading 'postMessage')
    at a.value (main.js?v=
    at aa (main.js?v=
    at vu (main.js?v=
    at t.unstable_runWithPriority (main.js?v=
    at Yo (main.js?v=
    at du (main.js?v=
    at tu (main.js?v=
    at Qa (main.js?v=
    at Fu (main.js?v=
    at main.js?v=

Which Web Meeting SDK version?

Meeting SDK Code Snippets
No customization, using the CDN folder sample app

To Reproduce(If applicable)
Steps to reproduce the behavior:

  1. Go to '
  2. Enter meeting id: [REDACTED]
  3. Enter password: [REDACTED]
  4. Try just get to the waiting room because the meeting will be over, but you should at least get to the waiting room

Here is a recording of the problem: Loom | Free Screen & Video Recording Software

Device (please complete the following information):

  • Device: Macbook Pro M1 Max
  • OS: macOS 12.0.1
  • Browser: Chrome
  • Browser Version 96.0.4664.110

Additional context
I was able to join through the official Zoom Web Client by clicking “join by browser”

Greetings, @Felippe,

Thank you for posting in the Zoom Developer Forum. I reviewed the video but can’t reproduce that behavior on my end so I will need additional information. Can you share the meeting configuration set for that meeting? If the meeting is scheduled via API, please share the create meeting API request. This will help diagnose what may be happening.

I will keep an eye out for your response.


1 Like

Thanks for the response!

This was someone else’s meeting. Is it not possible to join other people meeting with the SDK Client?

  1. Go to '
  2. Enter meeting id: [REDACTED]
  3. Enter password: [REDACTED]
  4. Try just get to the waiting room

@donte.S I’m repeating the same steps in a different meeting. Again, a meeting created by someone else, that just requires login (not even registration): Loom | Free Screen & Video Recording Software


Thank you for posting and calling attention to the behavior you are seeing. I’ve created an internal ticket to have this investigated further [ZSEE-37278]. More to follow as updates become available.


Thank you!

Before you getting an answer, can you just tell me if what I’m trying to do should be possible? Joining someone else’s meeting that requires login using the web SDK?

If it should be possible, I’ll wait, otherwise I have to change my plans now


Yes, you can join someone else’s meeting that requires login using the Web SDK.


Awesome!! That is great :grin: will wait for the reply


Pulled a new version of the Web SDK 2.1.1 and tested it again, and I can confirm sign-in with Only authenticated users can join meetings from Web client and waiting room enabled works. Can you test again and with the sample app and let me know if the behavior persists? Here is a loom video for your reference

Hi @donte.S! I was able to login with my localhost. But deployed version running under a URL won’t run it. Is there any special kind of configuration that I need to do related to my domain?

Can you test yourself log in in a login-required-meeting using this client?

Same code works on localhost

@donte.S Hi! Bumping this up. I’ve came to a way of replicating the problem, which is running the default repository with no modifications in the cloud.

What changes should I make to enable authentication when I deploy instead of running locally?


The authentication workflow should work the same when deployed. It seems like the behavior you are seeing may be related to your network firewall settings. When testing, be sure the appropriate inbound and outbound rules are set for the cloud provider hosting your Application. Down below, I’ve linked our Zoom network firewall or proxy server settings help documentation for reference: