When a locked item is purposely unlocked, it is possible for two
versions of the same file to exist in different user sandboxes. When both
are submitted to staging, being routed first through the appropriate
workflow if one is defined, the file to complete submission first updates
the staging store. When the second file completes submission and attempts
to update the staging store, a conflict is detected.
To resolve the
conflict, you must revert the conflicted content item, reapply your
changes, and resubmit the item.