You have not yet defined parameter &1 for &2 (&3)

What causes this issue?

You have not yet entered all of the parameters necessary to define a
parameter configuration. You can only omit an optional parameter if you
are not going to use it. Once you have entered an optional parameter for
a higher-level value, you have to enter that value for all other
higher-level values. You have not done this for parameter &v1&.

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?

Define the missing optional parameters for the higher-level parameter
&v2& (&v3&).

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.