Enter a value for season &2 for operand &1

What causes this issue?

You tried to create values for operand &v1& that are not assigned to a
season. However, a <DS:DE.ERSATZWERT>replacement value</> for season
&v2& has been defined for operand &v1&. As a result, the creation of
season-independent values for the operands is not allowed.

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?

Create values for season &v1& for operand &v1&.

Error message extract from SAP system. Copyright SAP SE.