[REQUEST]How to fix it?

I followed the guide : [Only registered and activated users can see links. Click Here To Register...]
When buying items that modify disconnecting me!

Check that you have the item(s) to be able to have a stack of them for the same amount as it is on your Item Mall, for example, that you have the Rec Runes at 255 if it shows like that on the Item Mall, because if on the Item Mall you have it that the user will get that many and you have the count for that item to be less, you will get this kind of error

You say for example if I put the summon party congregation in ShStudios (Count 255) in the DB <dbo.items <ItemID <100045 <Count also 255?

of course,
If you set an item max stack to 255 in client side, you should do it in server side too (dbo.Items)and if you set an product item (item mall) to 255 exemple 100082 255, it should be stackable to 255 or crash.

when item count is 255 you will receive "inventory is full" not disconect.
read this: [Only registered and activated users can see links. Click Here To Register...]
most of item mall disconect problem is SQL.