Saving/Publishing a Confluence Page gives "Unable to communicate with server. Saving is not possible at the moment." due to invalid Task due date.
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*Except Fisheye and Crucible
Summary
When attempting to save/publish a Confluence Page, Confluence throws the following error:
"Unable to communicate with server. Saving is not possible at the moment."
Diagnosis
Below Java runtime exception can be seen in the application logs after attempting to Save/Publish the Page:
java.lang.RuntimeException: Default date value must be strictly before Fri Dec 31 17:18:00 UTC 9999. Listener: com.atlassian.confluence.plugins.tasklist.listener.InlineTasksEventListener event: com.atlassian.confluence.plugins.tasklist.event.ConfluenceTaskV2CreateEvent
Caused by: net.java.ao.ActiveObjectsException: 1709555221694 Fri Dec 31 17:18:00 UTC 9999
Cause
There is a Task created in the Page that is given an invalid due date.
Example:
Confluence will only accept dates before Fri Dec 31 17:18:00 UTC 9999
Solution
Correcting the due date of the Task resolves the issue.