Meeting SDK Type and Version
Web Meeting SDK, @zoom/meetingsdk v5.1.2, Client View mode.
Description
We are integrating the Zoom Web Meeting SDK into a Nuxt 4 (Vue 3) application. Our implementation uses ZoomMtg.init() / ZoomMtg.join() in client view mode. We do not interact with,
configure, or manage the annotation system in any way — we rely entirely on the SDK’s built-in toolbar UI for annotation tools.
When a participant shares their screen and the host clicks the annotation pencil icon in the SDK toolbar, the error “Canvas is incorrect” appears intermittently. The error does not occur every time. When it does occur, the workaround is for the participant to stop and restart screen sharing, after which annotation works correctly.
Our application code contains zero annotation-related logic. The code that manages the Zoom session only handles: meeting initialization/joining, virtual background management, media device cleanup. I suspect this is a race condition internal to the SDK where the annotation overlay attempts to reference the sharing canvas before it is fully initialized.
Error
“Canvas is incorrect”
Troubleshooting Routes
- Verified COEP/COOP headers are correctly set on session routes:
- Cross-Origin-Opener-Policy: same-origin
- Cross-Origin-Embedder-Policy: require-corp
- Verified the zmmtg-root element is properly managed (shown on init, cleaned up only on leave)
- Verified no DOM manipulation in our code conflicts with the SDK’s internal canvas elements
- Verified media cleanup only runs on leave/page unload, never during an active session
- Searched forums for “Canvas is incorrect” postings.
How To Reproduce
- Authentication: JWT app type, signature generated server-side via Zoom Meeting SDK credentials
- Setup: Two participants — one as participant, one as host, both joining via Web Meeting SDK in client view mode
- Steps:
- Participant joins the meeting and starts screen sharing
- Host clicks the annotation pencil icon in the SDK toolbar immediately (within ~1-2 seconds) after the participant’s shared screen appears
- Result: “Canvas is incorrect” error appears in the SDK UI
- Workaround: Participant stops sharing, then starts sharing again. Annotation tools now work correctly.
- Browser: Chrome v145, macOS (single monitor)
- SDK Version: @zoom/meetingsdk v5.1.2 (also reproduced on v5.1.4)
- Rendering mode: Client View
Thank you for having a look!