Entry is required for for characteristic &1

What causes this issue?

You have not entered a value for characteristic &v1&. This entry is a
required entry.

System Response

You cannot save your information without entering a value.

How to fix this error?

Enter a value for &v1&.

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.