The error is due to the windows 10 update as mentioned by @Samwiseg0
Aug 08, 2018 08:28:22.468 [99628] ERROR - [Transcoder] [stream_segment,ssegment @ 01f5c040] Failed to open segment list 'http://127.0.0.1:32400/video/:/transcode/session/E34FFF57-B336-4F3C-9D27-437F5ED3CEB3/3b1da400-ee3e-49d8-b262-7bc99ded130f/seglist'
Aug 08, 2018 08:28:58.037 [99628] ERROR - [Transcoder] av_interleaved_write_frame(): Unknown error
Aug 08, 2018 08:28:58.039 [115340] ERROR - [Transcoder] Error writing trailer of media-%05d.ts: Invalid argument
You are lucky that this is a known issue but in future please check that you have debug logging enabled before uploading any logs !
See https://support.plex.tv/articles/201643703-reporting-issues-with-plex-media-server/
And for the windows 10 update bug see
