Function &1 is controlled by the field group; navigation is not possible

What causes this issue?

The settings for function &V1& are such that this function can be
activated by way of a field group. In this case you cannot activate the
function by way of the activity/view, and/or activity/view/screen
sequence category.

System Response

Information message, navigation is denied.

How to fix this error?

If you want to activate the function by way of the activity/view, and/or
activity/view/screen sequence category, you must select this option in
the detail screen for the function.

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.