How To Fix SMT156 - Only letters and the special character "_" are allowed for mappings

SAP Error Message - Details

• Message type: E = Error

• Message class: SMT -

• Message number: 156

• Message text: Only letters and the special character "_" are allowed for mappings

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message SMT156 - Only letters and the special character "_" are allowed for mappings ?

  The SAP error message SMT156, which states "Only letters and the special character '_' are allowed for mappings," typically occurs in the context of SAP's data mapping or transformation processes, such as in SAP Data Services or SAP Process Integration (PI). This error indicates that the naming convention for a mapping or transformation object does not comply with the allowed character set.
  Cause:
  The error is triggered when the name of a mapping, transformation, or related object contains invalid characters. According to the error message, only letters (A-Z, a-z) and the underscore character (_) are permitted. This means that any other characters, such as numbers, spaces, or special symbols (e.g., @, #, $, etc.), will lead to this error.
  Solution:
  To resolve the SMT156 error, follow these steps:
  
  
  Identify the Object: Determine which mapping or transformation object is causing the error. This could be a mapping name, transformation name, or any related identifier.
  
  
  Rename the Object: Change the name of the object to comply with the naming conventions. Ensure that:
  
  The name consists only of letters (A-Z, a-z) and underscores (_).
  Avoid using any numbers, spaces, or special characters.
  
  
  
  Check for Consistency: If the mapping is referenced elsewhere in your project, ensure that all references are updated to reflect the new name.
  
  
  Test the Changes: After renaming, re-run the process that triggered the error to confirm that the issue has been resolved.
  
  
  Related Information:
  
  Naming Conventions: Familiarize yourself with the naming conventions and best practices for SAP objects. This can help prevent similar errors in the future.
  Documentation: Refer to the official SAP documentation for the specific module you are working with (e.g., SAP Data Services, SAP PI) for more details on naming conventions and error handling.
  Error Logs: Check the error logs or messages in the SAP system for additional context or related errors that may provide further insight into the issue.
  
  By following these steps, you should be able to resolve the SMT156 error and ensure that your mappings adhere to the required naming conventions.