To resolve inventory recalculation cancellation error for Weighted Average date setting error may be like this
Item xxxx
could not delete weighted average inventory closing transaction on item xxxx on date dd/mm/yyy
Then solution is you should apply following hotfix.
KB973239
Item xxxx
could not delete weighted average inventory closing transaction on item xxxx on date dd/mm/yyy
Then solution is you should apply following hotfix.
KB973239