QBO Business Validation Error: Select a product or service

Error

The Product Types have no mapping or Type Cross Reference in ConnectWise Manage
The Sales transaction has item reference for Purchase item in line in QBO or a Purchase transaction has item reference for a Sales item.

Ensure the Product Types mapping is enabled or has Type Cross Reference to create the products as the correct type in Quickbooks Online. Please note that the new standard best practice for ConnectWise Manage is to only have 4 Product Types:
*Inventory
*Non-Inventory
*Service
*Other Charge
Note: To check this, in ConnectWise, go to System > Setup Tables > Product Type List. For each and every product type (including those that are inactive) you need to select the Type Cross Reference.
If the record that is not posing is a sales transaction, in QBO, go to the Product/Service Information and make sure that the “I sell this product/service to my clients” is checked. However, if the transaction that is not posting is a purchase transaction, make sure that the “I purchase this product/service from a supplier.” is checked.