I’m on Linux, not Win, but this was a problem I had a few years ago (back to back recordings cause the second recording to fail.) The resolution was to delete codecs, after which Plex will redownload codecs as needed.
Under Linux the process was to stop the Plex server process, go to the “codecs” directory, delete everything except the “.device_id” file, and then start the Plex server process. Here is a link to someone describing that process on Win.
