Mmm... Yes, that's an interesting bug indeed.
The board needs to close to ensure that no posts are made, which would cause bad things to happen while the prune process is occuring.
But at the same time, you'd need to view the posts, as you mentioned.
Admin-only off mode would be OK, but the prune utility works for moderators as well.
I'll figure out how to fix this one for the 6.7.0 release. (The scale of the bug is too large to safely fix in the upcoming 6.6.1 maintenance release.)
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Charles Capps
UBB.classic™ Developer
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