How To Fix WM390 - Not only mat.grp classes (026) are in use - all other mat. classes too

WM390 - Overview

• Message type: E = Error

• Message class: WM - IS-R Assortments

• Message number: 390

• Message text: Not only mat.grp classes (026) are in use - all other mat. classes too

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message WM390 - Not only mat.grp classes (026) are in use - all other mat. classes too ?

  The SAP error message WM390 indicates that there is an issue with the material group classification in the Warehouse Management (WM) module. Specifically, it suggests that the system is trying to process a material that is not only associated with the specified material group class (026) but also with other material classes. This can lead to confusion in the system regarding how to handle the materials.
  
  Cause:
  
  Material Classification: The material in question is classified under multiple material groups or classes, which can lead to conflicts in processing.
  
  Configuration Issues: There may be a misconfiguration in the material master data or in the warehouse management settings that does not align with the expected material group classes.
  Data Integrity Issues: There could be inconsistencies in the data, such as incorrect entries in the material master or warehouse management settings.
  
  
  Solution:
  
  
  Check Material Master Data:
  
  Go to the material master record (transaction code MM03) and check the classification of