Trade goods are no longer usable

Good question!

Accounting-wise, there is nothing else to be done, shit happens.

At the end of the year, around 31/12, you will need to enter your inventory. Your closing inventory will then be lower than it would otherwise be. This will have an impact on your accounts, simply by counting your inventory on 31/12 and then entering it.

I suspected it would be something like that, but thank you for confirming my suspicion.