Message type: E = Error
Message class:  FMHIE - Budget Hierarchies 
Message number: 815
Message text: Budget address is not a root node (document &1)
The budget address &V2& is not consistent with the distribution check
restriction rules activated for specific budgeting processes. In the
budget document &V1& this budget address is used with a budgeting
process, for which the budget address must be a root node of the
multi-level budget structure. However, the budget address &V2& is not a
root node.
The system issues an error message and will not allow you to continue with this transaction until the error is resolved.
If necessary, change the hierarchy definition of the multi-level budget
structure for budget address &V2& or reverse the budget document &V1&.
Error message extract from SAP system. Copyright SAP SE.
The SAP error message FMHIE815, which states "Budget address is not a root node (document &1)," typically occurs in the context of budget management within the SAP system, particularly when dealing with funds management (FM). This error indicates that the budget address you are trying to use is not a valid root node in the budget structure.
Cause: Non-root Budget Address: The budget address you are trying to use is not defined as a root node in the budget structure. In SAP Funds Management, a root node is a top-level node in the budget hierarchy that can have child nodes but does not have a parent node. Incorrect Configuration: The budget structure may not be configured correctly, or the budget address may not have been set up properly in the system. Document Type Issues: The document type you are using may not be compatible with the budget address you are trying to reference.
Solution: Check Budget
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