iPhone and iPad owners playing Pokemon GO have reported a severe issue after installing iOS version 1.85.4.
Upon starting Pokemon GO after installing the firmware update, the app will crash without warning. Niantic is aware of the issue and has recommended trainers to reinstall the app.
Trainers that have upgraded to iOS version 1.85.4, we're aware of an issue that causes the Pokémon GO app to crash upon loading. If you are experiencing this issue, please try to reinstall the app.
— Niantic Support (@NianticHelp) August 25, 2018
Are you experiencing this issue as well? Let us know in the comments.