The valuation &1 is already defined as a proposal

What causes this issue?

You have selected both valuation &1 and valuation &2 as your proposal.

System Response

The system selects the first selection you made.

How to fix this error?

Decide which valuation you want to use.

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.