Message type: E = Error
Message class:  FMBPASE - Messages for budgeting service enabling 
Message number: 050
Message text: Only BudgetRegisterCode 4 allowed in Controlling
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The SAP error message FMBPASE050 indicates that there is an issue with the budget registration code being used in a controlling (CO) context. Specifically, the message states that only Budget Register Code 4 is allowed in the controlling area for the transaction you are trying to execute.
Cause: This error typically arises due to one of the following reasons: Incorrect Budget Register Code: The system is configured to only allow Budget Register Code 4 for certain transactions in the controlling area. If you are trying to use a different budget register code, the system will throw this error. Configuration Settings: The controlling area may have specific settings that restrict the use of budget register codes. This could be due to the way the budgetary control is set up in the system. Transaction Type: The transaction you are attempting to execute may only be compatible with Budget Register Code 4, and using any other code will
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