Use only specific tax codes or only "**"

What causes this issue?

During transactions which are subject to withholding tax, a check and
calculation of input tax can only be correctly carried out if a tax
code is explicitly specified for all incoming line items or '**' is
used.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Change the incoming line items correspondingly.

Error message extract from SAP system. Copyright SAP SE.