How To Fix DT255 - No type was defined for field &

SAP Error Message - Details

• Message type: E = Error

• Message class: DT - Table activation (incl. indexes)

• Message number: 255

• Message text: No type was defined for field &

What causes this issue?

For the given field, you did not assign an active type and you did not
assign the data type and length by direct type entry. However, a field
requires one of these two entries.

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?

Assign an active type to the field or directly enter the data type and
length.

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 DT255 - No type was defined for field & ?

  The SAP error message DT255 ("No type was defined for field &") typically occurs when there is an issue with the data dictionary in SAP, specifically when a field in a structure or table does not have an associated data type defined. This can happen in various scenarios, such as during the creation of a new table, structure, or when modifying existing ones.
  Cause:
  
  Missing Data Type: The field in question has not been assigned a data type in the data dictionary.
  Inconsistent Data Dictionary: There may be inconsistencies or corruption in the data dictionary.
  Transport Issues: If the object was transported from one system to another, the data type might not have been included or defined properly.
  Custom Development: If you are working with custom developments (like Z-tables or Z-structures), the developer may have forgotten to define the data type for a field.
  
  Solution:
  
  
  Define the Data Type:
  
  Go to the Data Dictionary (transaction SE11).
  Locate the table or structure that is causing the error.
  Check the field definitions and ensure that every field has a valid data type assigned.
  If a field is missing a data type, define it appropriately (e.g., CHAR, NUMC, etc.).
  
  
  
  Check for Transport Issues:
  
  If the issue arose after a transport, check the transport logs to ensure that all necessary objects were included in the transport request.
  If needed, re-transport the object or manually adjust the definitions in the target system.
  
  
  
  Activate the Object:
  
  After making changes, ensure that you activate the table or structure to apply the changes.
  
  
  
  Check for Dependencies:
  
  If the field is part of a larger structure or is used in other objects, ensure that all dependencies are correctly defined and activated.
  
  
  
  Consult Documentation:
  
  If you are unsure about the appropriate data type, refer to SAP documentation or consult with a colleague who has experience with the specific data model.
  
  
  
  Related Information:
  
  
  Transaction Codes: 
  
  SE11: Data Dictionary
  SE14: Database Utility (to check for inconsistencies)
  SE80: Object Navigator (to view related objects)
  
  
  
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  
  
  Debugging: If the error persists, consider using the debugger to trace where the error is being triggered, which may provide additional context.
  
  
  By following these steps, you should be able to resolve the DT255 error and ensure that all fields in your data dictionary objects are properly defined.