An issue does not get synchronized and appears in the troubleshooting section with the category Cannot add or remove watcher. There can be different causes for each error messages. This article will explain the cause and solution of each error message.
Explanations & Solutions
Cause: The user name contains characters not accepted on the target system.
Solution: Verify the characters used in the username and remove any special characters.
Cause: The Backbone synchronization user does not have the right permissions or 'Customer one' cannot watch the issue.
Solution: Make sure that the Backbone synchronization user has the 'Manage watcher list' and 'View voters and watchers' project permissions and if missing grant them. Also make sure the affected user has the necessary rights to watch the issue.
Issue/user does not exist
Cause: The related issue or watcher does not exist.
Solution: Verify if the affected issue and the user you want to add to that issue exists in the target project.
Cause: An unidentified error occurred.
Solution: There is no standard solution for these errors. Please try one of the solutions above or let us investigate this further by following these steps: