Moved to a main sub-forum directly under staff-only CATEGORY. In Node Tree view, appears in list as expected (still labeled as CATEGORY of course). Also appears as expected in "normal forum view" when viewing staff-area CATEGORY and sub-forums. GOOD!
Click on the its name to confirm contents still intact (sub-forums, threads etc). Oops! This Server Error pops up. BAD!
Presume problem is, a CATEGORY can't reside beneath a sub-forum. Correct? Options? Can I "demote" so no longer a CATEGORY, but in doing so, preserve its sub-forums/threads/posts? Thus, allowing desired placement, archived in staff-only area, but not as a CATEGORY.
Solutions/education gratefully accepted!