How To Fix MD_SUBSTN031 - Control cannot be blank

SAP Error Message - Details

• Message type: E = Error

• Message class: MD_SUBSTN - Messages for Master Data Substitution

• Message number: 031

• Message text: Control cannot be blank

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

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Smart SAP Assistant

• What is the cause and solution for SAP error message MD_SUBSTN031 - Control cannot be blank ?

  The SAP error message MD_SUBSTN031: Control cannot be blank typically occurs in the context of Material Management or Production Planning modules when there is an issue with the configuration of a substitution or control parameter that is required for a specific process.
  Cause:
  
  Missing Control Data: The error usually indicates that a required field or control parameter has not been filled in. This could be due to incomplete configuration or data entry in the relevant transaction.
  Incorrect Master Data: The master data for materials, BOMs (Bill of Materials), or routing may not be properly set up, leading to missing control information.
  User Input Error: During the transaction, the user may have inadvertently left a required field blank.
  
  Solution:
  
  
  Check Configuration: 
  
  Navigate to the relevant configuration settings in SAP (e.g., SPRO) and ensure that all necessary control parameters are defined and not left blank.
  Verify the settings for substitution strategies, if applicable.
  
  
  
  Review Master Data:
  
  Check the material master data, BOMs, and routing to ensure that all required fields are filled out correctly.
  Ensure that the control parameters related to the material or process are properly maintained.
  
  
  
  Data Entry:
  
  If the error occurs during a transaction, review the input fields to ensure that all required fields are filled in.
  If you are using a custom transaction or program, ensure that the logic correctly handles all required fields.
  
  
  
  Consult Documentation:
  
  Refer to SAP documentation or help files related to the specific module you are working with for additional guidance on required fields and configurations.
  
  
  
  Testing:
  
  After making changes, test the process again to ensure that the error does not reoccur.
  
  
  
  Related Information:
  
  Transaction Codes: Depending on the context, you may be using transaction codes like MD01 (MRP Run), MD02 (Single-item, single-level planning), or others related to material planning.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message. You can search for the error message in the SAP Support Portal.
  User Forums: Consider checking SAP community forums or user groups for similar issues and solutions shared by other users.
  
  If the problem persists after following these steps, it may be beneficial to consult with your SAP support team or a functional consultant who specializes in the relevant module.