Canvas Publish returns “Canvas file not found” even though the canvas renders (Windows, 3.19.13)

Where does the bug appear (feature/product)?

Cursor SDK

Describe the Bug

Cursor version: Help → About Cursor. You’re on 3.19.13 (dd066f332fcea7382764400fde902f61920648d0, 2026-09-04).
OS: Windows 10 10.0.26100
Expected: Publish opens a team share dialog and copies a share URL.
Actual: Toast: Canvas file not found. Canvas still renders. Console is silent on click.

Summary
Every local .canvas.tsx under .cursor/projects//canvases/ fails to publish with “Canvas file not found.” The canvas compiles and renders. A 20-line smoke-test canvas fails the same way. Publish worked on this machine the previous day.

Steps to Reproduce

Steps

Open a rendered canvas (rolling gf-delivery-metrics.canvas.tsx, dated snapshot, or a new publish-smoke-test.canvas.tsx).
Wait until the dashboard paints (status file is {“status”:“rendered”}).
Click Publish.

Expected Behavior

Expected
Share dialog / team share URL.
Actual
Info toast: “Canvas file not found.” No network request, no DevTools console activity from the click.

Investigation notes

Share action passes plan/team/privacy gates (ShareCanvasAction then calls shareCanvas).
Failure is status: “canvas-missing” from getShareArtifact.
Canvas server keys registrations with sha256(“canvas:” + path).slice(0, 12). Lookup does not read the filesystem.
Same file hashes to different IDs depending on path spelling:
c:\Users... → 20dd7fd6425f
C:\Users... → aae65cb5e560
c:/Users/… → 57fa2fca5a79
Workbench shareCanvas normalizes with path.normalize(t.replace(/\/g,“/”)) before calling the provider. If register used a different spelling than share, the map miss is guaranteed.
Full process kill + relaunch, opening the canvas from the Canvases list, and a never-opened smoke test all still fail.
Canvas server on 127.0.0.1:61044 returns 403 to unauthenticated probes.

Operating System

Windows 10/11

Version Information

About Cursor. You’re on 3.19.13

For AI issues: which model did you use?

Auto Balance

Additional Information

I have been using this weekly so I’d love to have this fixed soon.

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

3 posts were merged into an existing topic: Canvases stored under per-launch temp project key — Publish fails with “Canvas file not found” (Windows, standalone/Glass app)