Error: Incompatible bundle version or engine version detected. You cannot connect to a session created using a different bundle/editor version.

Hi @scott_euser

With the Core update a CKEditor 5 version had changed, which currently is used as bundle version for the sessions.
On render, the content is taken from database without any request to the cloud or on-premise server so that is expected to work fine.
Inability to edit content is indeed caused by issue related to that error message. The module contains code to flush collaborative sessions in case cloud version and local are different, however if there is another user currently in session it won't happen.
What is more in current state there is global flush call implemented, and if some session has active user it won't force flush that sessions and all unprocessed sessions (I don't know what is the order of flushing all sessions), that may include the session for the node user tries to edit. The implementation is bad also because it will attempt to flush also sessions for nodes created after the update.

I'll post a fix that should resolve the issue changing the flush command to act only on collaboration document that is being loaded.

Thanks for the details. It's just in a staging env as the client is trialling your offer (you've sent them the quote), so I do think it's just 1 user so perhaps this is not applying:

however if there is another user currently in session it won't happen

But hard to say for sure.

It would be good to have some way to trigger the flush then as of course we would have an unhappy client if all of a sudden they are no longer able to edit e.g. 5 nodes and forced to recreate them. E.g. A drush command (but maybe that's what you mean by the global flush command).

In any case thanks for looking into it!

By flushing session I meant an API call to the cloud or on-prem server which will allow to connect users with new bundle version.

I've added a drush command cke5_premium_ffacs which force flushes all sessions (even with connected users), however with single session flushing at a time the issue you encountered should be resolved. Unless there is an active user in the document which user is trying to edit - for such case I'll see if we can add a notification message that will appear in the editor window.

Hard to test this until next upgrade but it seems like it should not hurt to get this in and we can re-open if the issue recurs?

Drupal 11 will have CKEditor 5 updated to v42.0.0 - final relase this week.
However you can simulate library version change for premium features module with the simple patch I attached.

For now their trial has expired so I am unable to test even with that sorry.

Closing as we could not reproduce the issue.