Thanks for letting us know about this! Our team is going to reach out to you to collect more details and investigate your instance

Thanks a bunch!

Here is the reason behind these error messages:

{"message":"Email Not Found. "} -this means that the client did not have an email address at the time of sync. An email address is required to create/associate a client in QuickBooks

{"message":"invalid_grant"}  - This means the token for QuickBooks has expired. To fix this, return to the app market and sign into QuickBooks again. From there, you will be able to reauthenticate the account

Thank you, and if you run into anything else please leave another comment or post