How do I Resolve"Sales Class is not set up" when creating an Invoice?

You will either need to disable class tracking in QuickBooks or assign the proper classes in Acctivate configuration management based on sales/COGS configuration.

When creating an Invoice from a Sales Order and you receive a message stating "Sales Class is not set up" resolve this by reviewing the Class Tracking options.

QuickBooksClassTrackingPreferences

You will either need to disable class tracking in QuickBooks (Edit -> Preferences -> Accounting -> Company) or assign the proper classes in Acctivate configuration management based on sales/COGS configuration.