If like me you get this dreaded message at midnight when urgently trying to upload your latest masterpiece of cinematic art to YouTube from Compressor, follow the steps below. 1) In Compressor, click ‘Add File’. 2) Select the video source you want to share, then click ‘Add’. 3) Choose ‘Publish to YouTube’. 4) Choose a location, then click ‘OK’.5) In the Action area of the inspector, choose ‘Save Only’ from the ‘When done’ pop-up menu. 6) Click ‘Start Batch’. 7) Sign in to YouTube and upload your video file.
Update [12.12.2019] Updating to v.4.4.6 made no difference.