Hey Marko,
I can't open your items.otb, neither the .spr or .dat in any type of editor.
The weird thing is, the sprites work in my tibia server.
I tried using items editor, lapis editor and got not luck with the items.otb.
In Item editor, I get a message about client version 64, when using your Tibia.dat, Tibia.spr with your items.otb:
View attachment 95463
Lapis editor does not even output anything useful, it just stays stuck in Loading graphics forever.
Then, when I try to open your .spr and .dat in the object builder. When selecting the file, the signature and the sprites show up looking like they are loading:
View attachment 95464
However, when I try to open the file, it logs the following error:
View attachment 95465
I'm using Object Builder version 0.5.5.
I must say I'm stuck, because I can't inspect any of the items and I need to inspect somehow which items are included, otherwise it is not possible to switch some of the sprites that are wrong in my items.xml and in the tiles.
EDIT:
Looks like I have the same error from object builder in the item editor:
View attachment 95466