Known Issue - 2020.4 - Failed to Retrieve Tax Code, when Tax Code is NULL

We have logged a ticket with ConnectWise advising the issue.

You may request updates to this ticket and advise if you are affected by this issue:

ConnectWise Ticket: #14536666 

Date Reported: 16th of March 2021

Issue

The underlying message being returned:  'BadRequest' - { "code": "InvalidPatch", "message": "Null object cannot be converted to a value type."} has been an indication that the Vendor Tax code has not been set for the Vendor, which in turn is causing an invalid post for creating the batch in ConnectWise.

How do we know it's an issue?

When syncing a Purchase Order with 'Vendor Tax' selected, the sync results in a failure, specifically

Failed calling GET https://aus.myconnectwise.net/v4_6_release/apis/3.0/finance/taxCodes/1? resulted in error code: 'Forbidden' - { "code": "Security", "message": "You do not have security permission to perform this action." } And a further error: error code: 'BadRequest' - { "code": "InvalidPatch", "message": "Null object cannot be converted to a value type." }

The underlying issue is that a Tax Code has not been set for a Vendor in ConnectWise where the option is selected in Wise-Sync to use the Vendor Tax Code. It indicates that the record was batched, but the error indicates that there was a critical failure.

Workaround

Setting the Tax Code for the Vendor in ConnectWise resolves the issue (ConnectWise Manage > Company > Company Finance screen > Tax code) or via the Mass Maintenance screen