It seems that some cross-wording of variables was created within the scripts:
1. "forum_dest" was used rather than "forum" (old forum).
2. "merge" and "move" were swapped in one place.
and fixed an unreported bug:
3. the link for "moved post notice" was broken.
all fixed now.
BlackMale, thanks for catching and reporting this
it should be corrected with the UBB.thread 7.7.2 release!