This quick post is about an error while posting a sales order. For functional they know where is the missing piece but if you need some process to test one of your development, I would suggest to dig yourself before asking a functional folk.
Error: Account number for transaction type Cost of goods sold, invoiced does not exist.
Reason: Inventory posting have missing setup:
Solution: Go to Inventory > Setup> Posting > Posting
Check if the respective setup is missing. If yes Add record accordingly.