On December 18th, 2019, Intuit will discontinue all support for OAuth 1.0. Older versions of Scan2Invoice need to be upgraded the use a newer security protocol.
Older versions of Scan2Invoice might get the following error message when trying to connect to QuickBooks Online:
NEW Third-Party App Security Requirements:
This problem is resolved in the latest version of Scan2Invoice. To upgrade you need to download and install the latest version from the link below:https://www.scan2invoice.com/get-scan2invoice/
Please see below for a detailed explanation from Intuit:
NEW Third-Party App Security Requirements
At QuickBooks, ensuring your data security is our top concern, we have enhanced our security requirements for protecting your data starting December 18, 2019. Prior to us rolling out these enhancements, we have reached out to third-party app developers and asked them to align with our new security requirements. At this time, some of the apps may not be fully compliant with our new security requirements.
As a result, beginning on December 18, 2019, we are not allowing new connections to this app.
We apologize for this inconvenience. Please contact the developer of the app to understand where they are in supporting the latest QuickBooks security requirements.
Thank you for your business and we look forward to continuing to serve you.