Thanks for reaching out to us today, kareemkaram!
I appreciate the details you have provided about the issue when integrating your QBO with ERPAG. I can add some information about the error message you're getting.
May I know if you're using the QuickBooks International version? This will help us narrow things down.
At the moment, the ERPAG application will only work with the QBO US versions. You'll normally receive the connection error if you're using any QuickBooks versions outside United States.
You can, however, check the ERPAG Support Team for other options. They might have additonal workarounds they can provide to link your applications without any error messages. You may reach them through this link: https://apps.intuit.com/app/apps/appdetails?shortName=erpag&locale=en-us
Please feel free to get in touch with me if you need further assistance with QuickBooks. I'm always available to assist you whenever you needed me. Have a great day!