Package menus exist for packages that are not installed
I believe this is the result of upgrading when packages are not available for a new version.
I am on 2.3.1-release-p1 (amd64).
Both the iperf and ntopng packages are unavailable on this version.
On the service status page I see entries for both with an option to start them. I also see menu entries for their configurations but get a "no valid package defined" page when trying to open them.
There is no way to remove the entries for these missing packages.