How To Fix MD_SUBSTN018 - Groups are not allowed

SAP Error Message - Details

• Message type: E = Error

• Message class: MD_SUBSTN - Messages for Master Data Substitution

• Message number: 018

• Message text: Groups are not allowed

What causes this issue?

Application area does not support groups. For more information, refer to
Product Assistance for Product Substitution.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message MD_SUBSTN018 - Groups are not allowed ?

  The SAP error message MD_SUBSTN018: Groups are not allowed typically occurs in the context of Material Requirements Planning (MRP) or when dealing with substitution or planning groups in SAP. This error indicates that the system is trying to process a group of materials or items in a way that is not permitted.
  Cause:
  
  Incorrect Configuration: The error may arise if the system is configured to expect individual materials but is instead receiving a group of materials.
  Substitution Settings: If you are trying to substitute a group of materials instead of individual items, the system may not allow this operation.
  Planning Group Usage: The error can also occur if a planning group is being used in a context where it is not allowed, such as in certain MRP runs or when creating procurement proposals.
  
  Solution:
  
  Check Material Group Settings: Review the configuration of the material groups and ensure that they are set up correctly. Make sure that the materials you are trying to process are not grouped in a way that violates the system's rules.
  Use Individual Materials: If you are trying to perform an operation on a group of materials, consider processing them individually instead.
  Review Substitution Configuration: If the error is related to substitution, check the substitution settings in the material master and ensure that they are correctly defined for individual materials.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on the context in which the error occurs, as the solution may vary based on the specific transaction or process being executed.
  Check User Authorizations: Ensure that the user has the necessary authorizations to perform the operation on the materials in question.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as MD01 (MRP Run), MD02 (MRP for Single Material), or MD04 (Stock/Requirements List) to understand where the error might be occurring.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message. SAP frequently updates its knowledge base with solutions for common problems.
  Community Forums: Engage with SAP community forums or support channels where other users may have encountered and resolved similar issues.
  
  If the problem persists after trying the above solutions, it may be beneficial to consult with your SAP support team or a technical consultant who can provide more in-depth analysis and assistance.