Invalid Date Time Format Error Message

Suggestion Summary

Currently, when an user runs into an issue related to a invalid date/time entry in a Confluence page, instead of showing a friendly message, the application will display an error log.

Stack Trace

2017-09-27 10:24:39,069 ERROR [http-nio-8090-exec-23] [confluence.content.service.RenderContentCommandImpl] validateInternal Error generating preview.
-- referer: https://confluence.host.com/pages/resumedraft.action?draftId=12345&draftShareId=usuihsd-123sjhdas-31232 | url: /pages/rendercontent.action | traceId: 66441c0e06667035 | userName: user | action: rendercontent
com.atlassian.confluence.content.render.xhtml.XhtmlException: RuntimeException occurred while transforming editor format to storage format (com.atlassian.confluence.content.render.xhtml.XhtmlException: An error occurred due to invalid date time format during unmarshalling a time from storage format.)

Expectation

If an user attempts to edit a page that has an invalid date/time entry, the un-marshaller will fail. Instead of gracefully informing the user that there's a wrong entry somewhere, Confluence will display above stack trace and the editor will state that the server can't be contacted at that time. Users do expect a friendly message, like a banner in the top of the page, explaining that there's a problem with content while the stack trace above is logged in the backend.

Other Bugs

This is similar to CONFSERVER-33534.