Issue Summary

The background WebDAV session cleanup job can fail when reading a saved editing session containing a document lock. The failure generates repeated log messages, prevents that cleanup run from completing, and may prevent further edits/updates to document.

Steps to Reproduce

1. Enable Edit in Office 
2. Attach a Word document to a Confluence page
3. Open a document using Edit in Office and begin editing
4. Keep the editing session open and wait for the WebDAV cleanup job, which runs every five minutes
5. Check Confluence logs

Expected Results

Editing documents is not impacted. The cleanup job reads saved sessions successfully and removes sessions that have been inactive for more than 30 minutes and are no longer being processed.

Actual Results

Subsequent edits/updates to the document may fail and confluenceDavSessionInvalidatorJobTrigger fails with:

com.fasterxml.jackson.databind.exc.InvalidTypeIdException:
Could not resolve type id
'org.apache.jackrabbit.webdav.lock.SerializableActiveLock'
as a subtype of `java.lang.Object`: no such class found 

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available