Message type: E = Error
Message class:  FKK_ID_XX_ODN - ODN message 
Message number: 105
Message text: Sub-ID &1 is assigned to document class &2
If you have assigned a number range to a document class, you should not
delete or change a sub-ID that is assigned to that document class.
The system issues an error message and will not allow you to continue with this transaction until the error is resolved.
Delete the assignment of the number range to the document class in the
Customizing activity
<DS:SIMG._FICAOD_ODNNR_DET>Assign Number Ranges to Company Codes and
Document Classes</> before you change or delete the sub-ID that is
assigned to the document class in the Customizing activity
<DS:SIMG._FICAOD_DOCCLS_DET>Assign Document Classes to Document Types
and Origin Keys</>.
Note that if a document has already been posted using the document class
and the assigned number range, you cannot delete the entry in the
Customizing activity <LS>Assign Number Ranges to Company Codes and
Document Classes</>.
Error message extract from SAP system. Copyright SAP SE.
The SAP error message FKK_ID_XX_ODN105 typically occurs in the context of the SAP Convergent Charging or Contract Accounts Receivable and Payable (FI-CA) modules. This error indicates that a specific sub-ID (sub-account) is already assigned to a particular document class, which can lead to issues when trying to process transactions or documents.
Cause: The error is generally caused by one of the following reasons: Duplicate Assignment: The sub-ID you are trying to use is already assigned to another document class, which violates the uniqueness constraint in the system.
Configuration Issues: There may be configuration settings in the system that are not aligned correctly, leading to conflicts in document class assignments. Data Integrity Issues: There might be inconsistencies in the data, such as incorrect entries in the configuration tables.
Solution: To resolve the error, you can take the following steps: Check Assignments: Use transaction codes like OBB2 or OBB3 to check the assignment of sub-IDs to document classes. Ensure that the
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