How To Fix LT166 - Relationship between masked storage types must first be defined

SAP Error Message - Details

• Message type: E = Error

• Message class: LT - LE-WM: View or Table Maintenance Error Messages

• Message number: 166

• Message text: Relationship between masked storage types must first be defined

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message LT166 - Relationship between masked storage types must first be defined ?

  The SAP error message LT166, which states "Relationship between masked storage types must first be defined," typically occurs in the context of warehouse management and inventory management processes. This error indicates that there is an attempt to perform a warehouse task or transfer that involves storage types that have not been properly defined in the system.
  Cause:
  The error is usually caused by one of the following reasons:
  
  Undefined Relationships: The storage types involved in the operation are masked (i.e., they are not directly accessible or are restricted) and do not have a defined relationship in the system.
  Configuration Issues: The configuration settings for the warehouse management system (WMS) may not have been set up correctly, particularly regarding the relationships between different storage types.
  Warehouse Process Types: The process types that govern how goods are moved between storage types may not be properly configured to handle the specific storage types involved.
  
  Solution:
  To resolve the LT166 error, you can follow these steps:
  
  
  Define Relationships:
  
  Go to the SAP Customizing Implementation Guide (IMG).
  Navigate to Logistics Execution > Warehouse Management > Master Data > Storage Types > Define Relationships Between Storage Types.
  Here, you can define the relationships between the masked storage types that are causing the error.
  
  
  
  Check Configuration:
  
  Ensure that the configuration for the warehouse management system is complete and correct.
  Verify that all necessary settings for storage types, warehouse process types, and movement types are properly configured.
  
  
  
  Review Warehouse Process Types:
  
  Check the warehouse process types that are being used for the transfer or task. Ensure that they are set up to handle the specific storage types involved.
  
  
  
  Testing:
  
  After making the necessary changes, test the process again to ensure that the error no longer occurs.
  
  
  
  Consult Documentation:
  
  If you are unsure about the configuration steps, refer to SAP documentation or consult with a SAP WM consultant for guidance.
  
  
  
  Related Information:
  
  Transaction Codes: You may need to use transaction codes such as SPRO (to access the IMG) or LT01 (to create transfer orders) to navigate through the necessary configurations.
  SAP Notes: Check for any relevant SAP Notes that may provide additional insights or updates related to this error message.
  User Roles: Ensure that you have the appropriate authorizations to make changes to the warehouse management configuration.
  
  By following these steps, you should be able to resolve the LT166 error and ensure that the relationships between storage types are properly defined in your SAP system.