No budget category defined for FM area &1

What causes this issue?

You have selected an FM area to which no budget category is assigned.

System Response

The system does not allow you to run the budgeting workbench with this
FM area.

How to fix this error?

Select another FM area or contact your system administrator to complete
the Customizing settings.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.