Legal document category differs for postings in number range &1

What causes this issue?

You tried to post a document in a number range with a
<DS:DE.RDSV_LEGAL_DOC_CAT>Legal Document Category</> that differs for
existing postings in this number range.

System Response

The system prevents the posting because such postings are not legal in
the country of the company code that you use.

How to fix this error?

You can only post documents with the same legal document category in a
number range.
<ZU>Note:</>
Documents of the legal category 'Invoice', 'Proforma Invoice', 'Debit
Memo', 'Credit Memo' must not be mixed in a number range.
The legal document category is determined by the document category
(VBTYP).

Procedure for System Administrators

Adjust the relevant customizing settings, BAdI-implementations or system
modifications that control the number range determination and the
document numbering in the system.

Error message extract from SAP system. Copyright SAP SE.