This TB is no longer in Helsinki City Museum cache and hasn't been there for several days. Hopefully the geocacher who's retrieved it will submit the proper log soon.
In case the geocacher won't do it in few days we need to mark the item as missing in order to keep the geocache's inventory correct.
Most likely the TB is, though, safe and sound in the hands of a geocacher who hasn't yet been able to submit the proper online log.