This happens when you try to sync your application but it doesn’t have a password set up yet.

What you can do?

Set a password for your application first before you update or sync it with QuickBooks. If you don’t know the password, contact your application’s support for help.

Note: If you still get this error, reach out to Intuit Support.

Reference: https://quickbooks.intuit.com/learn-support/en-us/set-up-payments/fix-common-web-connector-errors/00/203305