Xcode process launch failed: Security

Question

I have been developing an app for 1 or 2 weeks now and just yesterday I have updated my iPhone 5S to the iOS 8 GM. Everything worked fine and I could test on my device as well until I deleted the app from my phone and wanted to build again. The following error appeared:

Could not launch "My App" process launch failed: Security 

When I test with the simulator it works fine. Is this because of the iOS 8 GM update and how can I fix this launch problem? I want to be able to test on my iPhone and in the simulator.

Answer 1

If you get this, the app has installed on your device. You have to tap the icon. It will ask you if you really want to run it. Say “yes” and then Build & Run again.

As from iOS 9, it is required to go to Settings → General → Device Management → Developer App → Trust`.

On some versions of iOS, you will have to go to Settings → General → Profile instead.