Invalid signature genral app in production mode

Meeting SDK
1

Meeting SDK Type and Version

Zoom Web Meeting SDK – Version: 3.7.0

Description

I have a Zoom app listed on the Marketplace: VClasses App
The app is live in production and works as expected when creating and joining meetings using the same Zoom account (meeting1@vclasses.net) that is associated with the app.

However, when I create a meeting using another Zoom account (e.g., islam.samir30@gmail.com) — which is properly authorized through OAuth and connected — the student is unable to join the meeting via the SDK. The SDK throws an “Invalid signature” error.

Error

json

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{
  "method": "join",
  "status": false,
  "result": "Invalid signature.",
  "errorCode": 3712,
  "errorMessage": "Signature is invalid."
}

Signature payload example:

json

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{
  "appKey": "YCi8FhYWSfWZ2pn8Zq6UQg",
  "mn": "92284122690",
  "role": 1,
  "iat": 1750851377,
  "exp": 1750854977,
  "tokenExp": 1750854977
}

I confirmed the App Key and SDK Key match the Zoom app credentials:

  • App Key: YCi8FhYWSfWZ2pn8Zq6UQg
  • SDK Key: RrptOgc5ryaVhDVHy14hjRTGAN1vgHbk

Troubleshooting Routes

  • Verified meeting creation works for all accounts.
  • Verified SDK credentials are correct and used consistently.
  • Tested SDK signature logic with Zoom’s official signature generator tool.
  • Signature works only when the meeting is created with meeting1@vclasses.net.
  • Tested same logic on Zoom Web SDK Sample App from GitHub — same result.

How To Reproduce

  1. Set up a Zoom Meeting SDK app (type: SDK) with Web SDK enabled.
  2. Create a meeting using account A (meeting1@vclasses.net).
  3. Join via SDK – works :white_check_mark:.
  4. Create a meeting using account B (islam.samir30@gmail.com), authorized through OAuth, under the same app.
  5. Try to join via SDK – fails :cross_mark: with signature invalid error (3712).
  6. Both accounts are properly connected and meetings are created successfully via Zoom API.