If you get the following error:
Warning: Error in OpenConnectionBeginSession.
This application has not accessed this QuickBooks company data file before. The QuickBooks administrator must grant an application permission to access a QuickBooks company data file for the first time.
You may not be logged in as an administrator to your QuickBooks desktop account.
To resolve this:
Close QuickBooks and shut down the sync engine.
Verify you have closed ALL instances of QuickBooks in Windows Task Manager.
Open QuickBooks and log in as admin.
Connect again to Method via the sync engine.