Conversion failed. The transcoder exited due to an error (Memory Allocation failures)

This appears to be the same issue that I pointed you to earlier. All videos with TrueHD will fail transcoding, whether 4K or standard Blu ray. Seems to be caused by a memory leak. https://forums.plex.tv/t/optimizing-4k-titles-causes-plex-to-freeze-truehd-audio-the-problem/238970/17