hmm ... im not sure ob idm work on 8.1
when it works:
Open IDM, (

)
open the id list tool and find your id's and the Id's of the things what you will changed.
Press "Save" and gif it a name
Then klick on it and load it, then press "lock".
go to the main servers and go again in the english server.
your things are chaged bud ist crash wenn you go in a room. :c
changed the window to the orther programm of idm, gif it again a name, set it befor on "format2".
Then but all things off, klick of idm where you gif in the format2 the button "load".
Are you doing this switch with the windows shop an inventory and the things are back.
Go in a room ... an EVERYTIME!!! ...
PRESS BEVOR START/RDY EVERYTIME RESTORE :O
Wenn you not press ist the game will chrashed and you can do all again :c
so this was it XD
Everytime wenn you go out of a room press load, switch the windows shop and inventory and press in the room bevor start Restore :3
I hope i had helpet you

(Ps. sry for my bad english :c )