This error could appear in both version 9.3 of SAP and version 10.

 

In the draft document, go to the Accounting Tab, open the Installments window, click on Restore Default, Update, and try to post the document again, as shown below.

 

 

It should eliminate this error.

 

IMPORTANT: If you are using Service Layer, this error was sorted from the Avatax addon 24072900 version onwards.

 

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