Instruments > device grayed out

Question

I'm running an app on my iOS device but, in Instruments, that device is greyed out.

This also means I can't attach the process (Cant launch iOS app with Instruments on device). Is it anything to do with my earlier question: Instruments > Profile - Revoke and request

Xcode: 6.1.1 iOS: 7.1.2

Any idea why?

Answer 1

I only had to reboot my phone (not my Mac), and then the error went away (Xcode 9.2, iPhone X running 11.2.6).

Answer 2

i was having this issue and resolved it by

1. Unplugging my device
2. Turning my device off
3. Rebooted my mac
4. Turned device back on and plugged into computer after logging back in.

now it shows up in instruments. I tried unplugging device, restarting xcode, but that didn't work. rebooting everything is what did the trick for me.