cannot find remaining unassigned tasks in JQL filter

[Jason Herz]

I am trying to find all the tasks in my JIRA instance that have the assignee set to 'unassigned'. When I run a simple JQL statement: 'assignee is EMPTY' I get no results, but when I go to the Jira Settings>System> General Configuration and try to set the 'Allow unassigned issues' to OFF, I am unable, it says there are >100 issues set to unassigned and 2 projects with the default assignee set to unassigned. I checked EVERY project manually (which took forever) and I am 99% sure all the projects are set to the default assignee being the project lead. I did create an Archived project permission scheme as several projects are years old, but I have also verified that Browse and Administer permissions are set so that the Group: Administrators can browse and administer these projects (which I am a part of). Can anyone help me with this? I have spent several hours and am getting to the point of throwing something out the window. I appreciate any input and I hope to resolve this soon. Thanks for your time! 

[Andrew Morin]

I just ran the query in my Jira instance and got back a ton of issues.

assignee is EMPTY

Can you click on the hyperlink in the error output to go to the issues and/or projects? Then you can identify where they are at. Did you archive a couple projects possibly?