NSInternalInconsistencyException: ‘Invalid parameter not satisfying: !stayUp || CLClientIsBackgroundable(internal->fClient)’

I’ve managed to solve this by doing these two things:

• added UIBackgroundModes ‘location’ to Info.plist
• added NSLocationAlwaysUsageDescription to Info.plist

As of iOS 11, keys are named:

• NSLocationAlwaysAndWhenInUseUsageDescription and NSLocationWhenInUseUsageDescription