When use UIImagePcikerController to access photo library, an error is hit as below.
This app has crashed because it attempted to access privacy-sensitive data without a usage description. The app's Info.plist must contain an NSPhotoLibraryUsageDescription key with a string value explaining to the user how the app uses this data.
This issue is what is found in Ref [2]. Adding the following in Info.plist will resolve the issue
<key>NSPhotoLibraryUsageDescription</key>
<string>Allow the app to pick an image to share with others</string>
References
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1. http://www.codingexplorer.com/choosing-images-with-uiimagepickercontroller-in-swift/
2. http://stackoverflow.com/questions/37925583/uiimagepickercontroller-crashes-app-swift3-xcode8
