Same error as everyone else
Jul 25, 2018 19:29:04.232 [4592] ERROR - [Transcoder] [stream_segment,ssegment @ 04835180] Failed to open segment list 'http://127.0.0.1:32400/video/:/transcode/session/37618841fec2e8511b3e89d889778838/d69e290b-2266-4cc2-b23f-b65c6033f35d/seglist'
Jul 25, 2018 19:29:04.245 [7716] ERROR - [Transcoder] av_interleaved_write_frame(): Unknown error
Jul 25, 2018 19:29:04.358 [12692] ERROR - [Transcoder] Error writing trailer of media-%05d.ts: Invalid argument
which would suggest that it is the windows 10 update bug introduced by KB4338819 bug which Microsoft superseded with a second update 6 days later: KB4345421.
Please check that you do have the later update installed - if not you should be able to download it and install manually
I am seeing other 127.0.0.1 related errors - in communications between the Plex Media Server.exe process and the PlexScriptHost.exe python processes. It may well be due to the same bug - but worth checking that you do not have any proxy / vpn software running that may be causing this. check start / internet options / connections / LAN Settings / Proxy
Unrelated: Noticed that your Plex Media Server had a crash on 25th July at 19:25. I have located the crash report and will be submitting it to the development team together with the logs that are included in the zip you provided
