How To Fix GP120 - & may not be used as a planning dimension

GP120 - Overview

• Message type: E = Error

• Message class: GP - FI-SL and CO planning

• Message number: 120

• Message text: & may not be used as a planning dimension

What causes this issue?

Each dimension in the integrated FI-SL Customizing master records is
specified, whether it is used as a fixed field in planning (i.e.,
ledger entered on the initial screen) or whether it can be used in a
planning set. In your case, dimension &v1& is not marked as a dimension
that can be used in a set.

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?

Activate the 'Planning: Use in Set' indicator using transaction GCS1
for dimension &v1& or remove the dimension that is not allowed using
set maintenance from set &V2& which is entered in the planning
parameters.

Error message extract from SAP system. Copyright SAP SE.

GP120 - Details

• The SAP error message GP120 typically indicates that a certain characteristic or dimension cannot be used as a planning dimension in the context of SAP Business Planning and Consolidation (BPC) or SAP Integrated Business Planning (IBP). This error often arises when there is a mismatch in the configuration or when the characteristic is not set up correctly for planning purposes.
  Cause of Error GP120
  
  Incorrect Configuration: The characteristic may not be configured as a planning dimension in the system settings.
  Master Data Issues: The master data for the characteristic may not be properly maintained or may be missing.
  Dimension Type: The characteristic may be of a type that is not allowed for planning (e.g., it may be a text or non-numeric characteristic).
  Hierarchy Issues: If the characteristic is part of a hierarchy, there may be issues with how the hierarchy is defined or activated.
  Authorization Issues: The user may not have the necessary authorizations to use