Steps to reproduce:
1) Open the attached project.
2) Build the project for iOS.
3) On the iOS device, have some kind of an app, which can display 'Alert' type notifications (for example Facebook messenger, Slack etc.).
4) On the device go to Settings > Notifications > Select the app you will be using > Set the notification type to 'Alerts'.
5) Deploy the project to the device via Xcode.
6) Run the app.
- There is a rotating cube in the scene along with two GUI buttons, which are used to either enable or disable a 3 second delay during the execution of OnApplicationPause().
7) Press the GUI button 'Delayed Pause' - this enables the 3 second delay.
8) Make a notification show up on the device (send a Facebook/Slack message to it).
9) Dismiss the alert immediately.

- When the application is resumed after dismissing the alarm, the cube rotates for a brief moment after the 3 second delay ends, then the whole app hangs. If the alarm is dismissed after the delay ends, the app proceeds to run normally. If the 'Immediate Pause' button is pressed instead of delayed, the app resumes normally.
- If the app is paused by double-clicking the home button and then resumed, the issue does not reproduce as well.

Reproduced on:
5.5.0a1, 5.4.0b22, 5.3.4p6

Did not reproduce:
5.2.4f1

Devices:
iPhone 6, iOS 9.2
iPad Air, iOS 8.1.1