We just upgraded a site to OE 9.2A 20170710, multiple users reported seeing this issue:
"Critical error 1011 insufficient rights to create file in data directory"

They got it immediately after trying to use F6 on an item detail line(before even entering any search details), multiple users reported this issue at the same time but we were unable to re-create the issue minutes later. We were unable to find any unmatched OE finder files, nor multi-part files that were unmatched.

None of the users have permission issues inside the data directory. We suspect there is some process that is causing the lock, or perhaps 2 users tried to open the SF at the same time? I'll report more details as I get them but this is not a user permissions issue.