You would have to use Virus's Text To Item Code unless you find another one somewhere on the site or on another site. It never froze for me..
Do you have Action Replay Code Manager? If not, maybe you entered the code wrong. The reason why it deleted the original museum is because
search and replace searches for all of the user inputted item hex and replaces it with the user inputted item hex. In this case, for every museum
you had on your map, it got deleted with FFF1. If you can't get Text To Item to work, I would recommend modifying a slot modifier code.