How To Fix MM042 - The internal number already exists

MM042 - Overview

• Message type: E = Error

• Message class: MM - Messages for material master maintenance and Customizing

• Message number: 042

• Message text: The internal number already exists

What causes this issue?

All proposed internal numbers already exist in the database. This is
probably due to an error in user exit MGA00002. However, in rare cases,
this message may also be displayed if the user exit is not activated.

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 the user exit is activated, check its source code.
If the user exit is not activated, try creating the material again.

Error message extract from SAP system. Copyright SAP SE.

MM042 - Details

• The SAP error message MM042 ("The internal number already exists") typically occurs in the Materials Management (MM) module when there is an attempt to create or modify a material master record, and the system detects that the internal number being used already exists in the database. This can happen during various transactions, such as creating a new material or changing an existing one.
  Causes:
  
  Duplicate Material Number: The most common cause is that the material number you are trying to create already exists in the system.
  Number Range Issues: If the number range for material numbers is not configured correctly, it may lead to conflicts where the system tries to assign a number that is already in use.
  Data Entry Errors: Manual entry errors can lead to attempts to create materials with existing numbers.
  System Configuration: Incorrect configuration in the material master settings or number range settings can also lead to this error.
  
  Solutions:
  
  
  Check Existing Material