Parameter effectivity is not possible for context &

What causes this issue?

You can only maintain parameter effectivity for a context if an
effectivity type is entered.
Otherwise you can only enter the valid-from date and valid-to date.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.