How To Fix 26015 - Only external or mixed number assignment supported for document type &

26015 - Overview

• Message type: E = Error

• Message class: 26 - Dokumentenverwaltung

• Message number: 015

• Message text: Only external or mixed number assignment supported for document type &

What causes this issue?

You want to create a document of document type &V1& and want the system
to assign the document number <ZH>internally</>.
Via settings in the IMG (Document management), it is defined that
document number assignment for document type &V1& can only be
<ZH>external</> or <ZH>mixed</>.

How to fix this error?

Enter a document number, or the external part of a mixed document
number.
If your entry is purely numeric, you need to use the number ranges that
are defined in the IMG (Document management -> Control data -> Define
number ranges).

Error message extract from SAP system. Copyright SAP SE.

26015 - Details

• The SAP error message 26015, which states "Only external or mixed number assignment supported for document type &," typically occurs in the context of document number assignment in SAP, particularly when dealing with financial documents or other transactional documents.
  
  Cause:
  This error arises when the system is configured to use a specific type of number assignment for a document type that does not support the current configuration. The document type in question may be set to use internal number assignment, while the system is trying to process it with external or mixed number assignment. 
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check Document Type Configuration:
  
  Go to the configuration settings for the document type in question. This can usually be found in the SAP Customizing Implementation Guide (IMG) under:
  Financial Accounting (FI) > Financial Accounting Global Settings > Document > Document Number Ranges > Define Document Number Ranges.
  
  
  Verify the number assignment settings