AVAssetExportSession not working on devices, but working on simulator (AVFoundationErrorDomain Code = -11800, Unknown Error code -12780)

Question

EDIT: To make things easier to anyone interested in checking out this problem, I added a demo project to this github repository.

Issue<

Answer 1

The problem is that you're appending string to another string resulting in wrong path to the file like file:///var/mobile/Containers/Data/Application//DocumentsFinalVideo.mov

You should use appendingPathComponent() instead:

func createPath() -> URL {
    let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
    let documentDirectory = URL(fileURLWithPath: paths.first!)
    let url = documentDirectory.appendingPathComponent("FinalVideo.mov")

    if FileManager.default.fileExists(atPath: url.path) {
        try? FileManager.default.removeItem(at: url)
    }

    return url
}