AVExportSession with valid asset and preset errors in Video Toolbox.

Hello

I have a desktop AVFoundation app which uses AVFoundation to export a h.264 video to a viable preset.

I choose a preset from the results of exportPresetsCompatibleWithAsset:

I determine compatibility via determineCompatibilityOfExportPreset:
I then configure and run my export via exportAsynchronouslyWithCompletionHandler

My export completes, status for my AVExportSession is completed, there is no error attached, but my console log prints:

<<<< GVAVideoEncoder >>>> GVAVideoEncoder_SetProperty: AVF encoder error: VT GVAVideoEncoder_SetProperty  usage = 7
[14:38:25.128] GVAVideoEncoder_SetProperty signalled err=-12902 (kVTParameterErr) (bad usage) at /SourceCache/CoreMedia_frameworks/CoreMedia-1562.235/Sources/VideoCodecs/GVAMultiCodecs/GVAVideoEncoder.c line 761
<<<< GVAVideoEncoder >>>> GVAVideoEncoder_StartSession: AVF encoder error: VT GVAVideoEncoder_StartSession, unsupported usage 7
[14:38:25.128] GVAVideoEncoder_StartSession signalled err=-12903 (kVTInvalidSessionErr) (, bad usage, Encoder session was invalidated) at /SourceCache/CoreMedia_frameworks/CoreMedia-1562.235/Sources/VideoCodecs/GVAMultiCodecs/GVAVideoEncoder.c line 2122
[14:38:25.128] VTCompressionSessionCreate signalled err=-12903 (err) (VTVideoEncoderStartSession failed) at /SourceCache/CoreMedia_frameworks/CoreMedia-1562.235/Sources/************/VTCompressionSession.c line 967
[14:38:25.152] VTCompressionSessionSetProperty signalled err=-12900 (kVTPropertyNotSupportedErr) (Unsupported property key (it's not in the SupportedPropertyDictionary)) at /SourceCache/CoreMedia_frameworks/CoreMedia-1562.235/Sources/************/VTCompressionSession.c line 1818

I do have an encoded file, but that warning is troublesome no?

edit: I should note that my MacBook Pro (Retina, 15-inch, Mid 2014) and my Mac Mini (Late 2014) both report the above error in the console, but noth successfully export the asset.