This is not a big problem; I'm able to use the item in question. But, since I had a recipe for reproducing it I thought I would post.
1) Go to the tutorial's iron armor
2) Drag it to your inventory
3) Without moving anywhere else, drag it on top of your previously equipped, and quite fashionable, wood leggings
4) Iron armor appears in both the former location of the wood leggings, and also on top of the wood leggings
5) Equip the iron armor (clears the mixed sprite)
6) There now appears to be another iron armor in the chest.
7) Drag that iron armor to your inventory
8) "Item to buy not found" dialog appears.
If you walk away at this point, I believe everything works normally.
I've done this twice on two consecutive new characters using an incognito Chrome window.
This is not a big problem; I'm able to use the item in question. But, since I had a recipe for reproducing it I thought I would post.
1) Go to the tutorial's iron armor 2) Drag it to your inventory 3) Without moving anywhere else, drag it on top of your previously equipped, and quite fashionable, wood leggings 4) Iron armor appears in both the former location of the wood leggings, and also on top of the wood leggings 5) Equip the iron armor (clears the mixed sprite) 6) There now appears to be another iron armor in the chest. 7) Drag that iron armor to your inventory 8) "Item to buy not found" dialog appears.
If you walk away at this point, I believe everything works normally.
I've done this twice on two consecutive new characters using an incognito Chrome window.