Why is my profile not signed on iOS?

iOS VPN profiles are set up by the Hotspot Shield app. Profiles configured by apps cannot be signed, since they are configured directly instead of being downloadable files, and that naturally applies also to this profile.

We decided to move to application-configured profiles to achieve better performance. With this approach, you can turn  Hotspot Shield on and off through the app. It is no longer necessary to go to the iOS settings to turn our product on and off. 

The unsigned profile doesn't weaken the security of our product; it is configured directly by the signed application itself, and the connection is still as strongly protected as it has always been.