If no search terms can be generated from the search string (e.g. a single quote) on manage_user_page,
pushing the Apply Filter button throws

APPLICATION ERROR # 401

Database query failed. Error received from database was # 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') AND enabled = '1'' at line 1 for the query: SELECT count(*) as user_count FROM mantis_user_table WHERE (1 = 1) AND ( ) AND enabled = ?.
Please use the "Back" button in your web browser to return to the previous page. There you can correct whatever problems were identified in this error or select another action. You can also click an option from the menu bar to go directly to a new section.