If you encounter an error in the Sync Transaction Log that indicates that an order or a product cannot be updated because the item has been deleted, it is because the product record on QuickBooks has been deleted or made inactive.
Error Message:
2500: [Invalid Reference Id, Invalid Reference Id : One of the list elements assigned to this transaction has been deleted. Before you can modify this transaction, you must restore <name of product> (deleted).]
Until the product is restored on QuickBooks any order that uses this product will fail to be created or updated on QuickBooks.
Steps to Fix:
Log in to your QuickBooks Online account
Go to the Products and Services page (located in the gear icon menu)
Choose the Filter option and select "Inactive" from the status box
The list of products will now show only the inactive products
Now you can reactivate the product you need (referenced in the error above) by clicking "Make active"
Once you've done this, rerun the transaction from the BPro Transaction Log and the update will go through successfully.
You will need to repeat this process for any other inactive products that you use.
Important: Before making products inactive in QuickBooks in the future you should either delete them from BPro or make them inactive so that they won't be used accidentally in future orders. Existing orders that reference them will return the error above if you make updates to them, so make sure the product is no longer in use or that all orders that use it have been closed before making it inactive on QuickBooks.