[BUG] Canva connector — editing transactions fail with "Not allowed to access editing transaction" despite successful reads and reconnects

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In a Cowork session using the Canva MCP connector, start-editing-transaction and get-design calls succeed normally (reads and design copies work fine), but every perform-editing-operations call fails immediately with:

Not allowed to access editing transaction [id]

This happens on brand-new transactions with zero prior activity, so it isn't a stale-transaction issue.

Steps tried, none resolved it:

Reconnected the Canva account via Cowork settings (twice)
Fully restarted the Claude Cowork app
Retried on multiple different Canva designs, including ones never touched before

Reproducibility: 100% — every edit attempt fails the same way, while read operations on the same connector work normally throughout.

What Should Happen?

perform-editing-operations should successfully apply edits to an open Canva editing transaction, matching the behavior of get-design and start-editing-transaction (which work correctly).

Error Messages/Logs

Not allowed to access editing transaction [transaction_id]

Example: Failed to perform editing operations: Not allowed to access editing transaction 6930424144990790542 (Request ID: a1ec39202daa5bff-IAD)

This exact error occurs on every perform-editing-operations call, including brand-new transactions with no prior activity. Reconnecting the Canva account (twice) and fully restarting the Claude Cowork app did not resolve it.

Steps to Reproduce

1. Connect the Canva connector in Cowork.
2. Call start-editing-transaction on any design (succeeds, returns transaction_id).
3. Call perform-editing-operations on that same transaction_id with any valid operation (e.g. replace_text).
4. Observe failure: "Not allowed to access editing transaction [id]"
5. Reconnecting the Canva account and restarting the Cowork

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

N/A (Claude Cowork desktop app, not CLI)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

This bug occurred in Claude Cowork (desktop app), not the Claude Code CLI — several fields above (Claude Code Version, Terminal/Shell) aren't directly applicable and were filled with closest-available answers.

Issue: The Canva MCP connector's perform-editing-operations tool fails on every call with "Not allowed to access editing transaction [id]", while start-editing-transaction and get-design (reads) succeed normally on the same connector, same session, same designs.

Steps to reproduce:

1. Connect the Canva connector in Cowork.
2. Call start-editing-transaction on any design — succeeds, returns a transaction_id.
3. Call perform-editing-operations on that transaction_id with any valid operation (e.g. replace_text) — fails immediately.
4. Error: Not allowed to access editing transaction 6930424144990790542 (Request ID: a1ec39202daa5bff-IAD)

This reproduced on multiple different designs, including brand-new transactions opened seconds before the failed call (ruling out expired/stale transactions).

Attempted fixes, none resolved it:

• Reconnected the Canva account in Cowork settings (twice)
• Fully restarted the Claude Cowork app
• Retried across five separate transactions over the course of one conversation

Expected: perform-editing-operations should succeed on an open transaction, matching the behavior of the other Canva connector tools.