When the version of the company file and QuickBooks do not match, the Request Processor cannot start the session. The Request Processor, which we rely on to communicate with QuickBooks, goes through a checklist when an application attempts to start a session. Included in this checklist is ensuring the version of QuickBooks and the version of the company data file match one another, as seen in QuickBooks documentation linked below.

What happens in the BeginSession call?: https://developer.intuit.com/app/developer/qbdesktop/docs/develop/connections-sessions-and-authorizations

Before connecting, you will need to ensure the versions of the company file and QuickBooks match. If you have any further questions, you can reach out to us directly at [email protected].