Caution: You are activating the extended withholding tax functions

What causes this issue?

You are activating the extended withholding tax functions. Note that
you can use either classic withholding tax or extended withholding tax
functions within a company code, but not both.
You can change over from classic withholding tax to extended
withholding tax, but first you have to convert the datasets. If you
activate extended withholding tax without converting the datasets, this
leads to considerable inconsistencies in the datasets.

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?

If you have previously used classic withholding tax, read the
documentation about the migration tool for changing over from classic
to extended withholding tax. Do not activate extended withholding tax
yet.
If you have not previously used classic withholding tax, you can
activate the extended withholding tax functions.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.