Hello.
First of all, re-check everything that you've done.
Try to add the item to your inventory using the SMC feature :
Or by executing this :
declare @

varchar(64)
set @

= 'CharNameHere'
exec _ADD_ITEM_EXTERN @

,'ITEM_MALL_ITEM_NAME_HERE',1,0
If it crashes after you relog/recall then something is clearly wrong in the Database/Media.