When trying to create an Invoice for a Sales Order in which the Sales Order contains a non-inventoried item, labor item or shipping item, you may receive this message:
Invoice not released
Non-inventoried Cost Offset account for (Some Warehouse) is not set, Order ‘SomeOrderNumber’, Line Number ‘X’ (SomeProduct)
This message means the GL Account for non-inventoried items for the related Warehouse has not been set in Configuration Manager. To resolve, go up to File -> Configuration Manager. Drill down to Inventory -> Warehouse. Select the related Warehouse, then select the Non-Inventoried tab at the bottom. You will need to set the GL Accounts for these Item types here.
After saving and closing Configuration Manager, you should be able to properly create your Invoice now.