I have found this thread with the same error code, that the issue can be connected with timeRange. Hence, I have tested export without specifying the timeRange property of AVExportSession. It fails with the same error.

Hi, here is the session Optional(<AVAssetExportSession: 0x2816e4af0, asset = <AVComposition: 0x2814dda40 tracks = (     "<AVCompositionTrack: 0x2814db940 trackID = 1, mediaType = vide, editCount = 13>",     "<AVCompositionTrack: 0x2814a8800 trackID = 2, mediaType = soun, editCount = 13>" )>, presetName = AVAssetExportPresetHEVC1920x1080, outputFileType = public.mpeg-4) and here is the the error Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo={NSLocalizedFailureReason=An unknown error occurred (-16364), NSLocalizedDescription=The operation could not be completed, NSUnderlyingError=0x281b0c8a0 {Error Domain=NSOSStatusErrorDomain Code=-16364 "(null)"}}