Occasionally when syncing with QuickBooks Online, you maybe receive the error message 'Unknown QBO API response error message.'
What causes this sync error message?
This error message means that Quadient AP encountered a problem with QuickBooks Online's API when running a sync.
How to resolve this sync error message
First, check the Intuit Develops Status Page linked here to ensure that QuickBook Online is not encountering any issues with their API. If QuickBooks Online API highlighted below is showing anything other than 'Operational', please wait until Intuit has resolved the issue before running a sync again. 
If QuickBooks Online API is showing as operational please contact our Support Team for further assistance.
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