Allocations tracking library was not loaded in time and unable to see stack trace
I'm running into the issue on iOS 7 simulator. I still don’t know how to fix this, but I may have found a workaround.
- Tap on “Record button” to stop the instrument if it’s running.
- Select Instrument -> Delete ‘Allocations’ Instrument… menu. You can see only ‘Leaks’ in the Instruments
- Tap on “Record button” to star the instrument. Start your application on the simulator.
- Tap on Library button and drag “Allocations” onto Instruments. You can see 'Leaks' and "Allocations" in the Instruments
I can see the stack trace after Step 4.
I experienced this in Xcode 8.3 and it was caused by Build Configuration mismatch for Run and Profile. 
Profiler tried to run Release type of application which was not even built.
So it caused the error.
After changing Profile Build Configuration to product type that was already built, in my case Debug, it resolved the issue and Instruments worked again.
In my case it only works using the iOS simulator version 8.1 +.
Also, don't forget to change to 8.1 in the project Build Settings under iOS Deployment Target