Hopefully someone from Plex will chime in here. I did look through the log a little and found the below:
Jun 08, 2017 12:30:00.188 [8992] DEBUG - DVR:Grabber: Starting operation for ‘The Best of the Joy of Painting - E1 - Gray Mountain’.
Jun 08, 2017 12:30:00.188 [8992] DEBUG - Activity: registered new activity dd7e1158-b113-4228-bf16-128a171cb4de - Recording
Jun 08, 2017 12:30:00.188 [8992] DEBUG - DVR:Grabber: HDHomerun starting a media grab on device device://tv.plex.grabbers.hdhomerun/1054E25D tuner 0.
Jun 08, 2017 12:30:00.195 [8992] DEBUG - DVR:Subscription: Failed to resolve subscription for ‘guid: com.gracenote.onconnect://show/339998 thumb: http://tmsimg.plex.tv/assets/p339998_b_v5_ac.jpg title: The Best of the Joy of Painting type: 2 year: 1991’ to library item
Jun 08, 2017 12:30:00.197 [8992] DEBUG - DVR:Grabber: Saving recording to C:\Data\TVShows2.grab\e33432ee8d37f598f018a34a8b04de5b77b58827
Jun 08, 2017 12:30:00.198 [8992] DEBUG - DVR:Grabber: Going to record for 1800 seconds, final URL is http://192.168.1.2:5004/auto/v25.4?transcode=heavy
Jun 08, 2017 12:30:00.199 [8992] DEBUG - DVR:Grabber: Setting timer to stop grab of ‘The Best of the Joy of Painting - E1 - Gray Mountain’ in 1800 seconds.
Jun 08, 2017 12:30:00.200 [8992] DEBUG - DVR:Segmenter: Creating a new recorder for http://192.168.1.2:5004/auto/v25.4?transcode=heavy.
Jun 08, 2017 12:30:00.204 [8992] DEBUG - DVR:Grabber: Waiting for a tuner (2 available).
Jun 08, 2017 12:30:00.205 [8992] DEBUG - DVR:Grabber: Allocated a tuner (1 left)
Jun 08, 2017 12:30:00.206 [8992] DEBUG - We’re going to try to auto-select an audio stream for account 1.
Jun 08, 2017 12:30:00.206 [8992] DEBUG - Selecting best audio stream for part ID -1 (autoselect: 0 language: en)
Jun 08, 2017 12:30:00.206 [8992] DEBUG - Falling back to picking the first audio stream 1.
Jun 08, 2017 12:30:00.206 [8992] DEBUG - We’re going to try to auto-select a subtitle.
Jun 08, 2017 12:30:00.206 [8992] DEBUG - Audio Stream: -1, Subtitle Stream: -1
Jun 08, 2017 12:30:00.207 [8992] ERROR - Unable to find title for item of type 5
Jun 08, 2017 12:30:00.207 [8992] DEBUG - MDE: analyzing media item -1
Jun 08, 2017 12:30:00.207 [8992] DEBUG - MDE: : no direct play video profile exists for http/mpegts/
Jun 08, 2017 12:30:00.208 [8992] DEBUG - MDE: : no direct play video profile exists for http/mpegts//
Jun 08, 2017 12:30:00.208 [8992] DEBUG - MDE: : codec is unavailable for analysis
Jun 08, 2017 12:30:00.208 [8992] DEBUG - MDE: : codec is unavailable for analysis
Jun 08, 2017 12:30:00.208 [8992] ERROR - Unable to find title for item of type 5
Jun 08, 2017 12:30:00.208 [8992] DEBUG - MDE: : selected media 0 / -1
Jun 08, 2017 12:30:00.209 [8992] DEBUG - Cleaning directory for session 34c0703b-370a-43fd-9033-815376ccbb01 ()
Jun 08, 2017 12:30:00.209 [8992] DEBUG - Starting a transcode session 34c0703b-370a-43fd-9033-815376ccbb01 at offset -1.0 (state=3)
Jun 08, 2017 12:30:00.210 [8992] DEBUG - Streaming Resource: Added session 04C4B060:34c0703b-370a-43fd-9033-815376ccbb01
Jun 08, 2017 12:30:00.215 [8992] DEBUG - Job running: EAE_ROOT=’\?\C:\Users\Mike\AppData\Local\Plex Media Server\Cache\Transcode\Sessions\EasyAudioEncoder’ FFMPEG_EXTERNAL_LIBS=’\\?\C:\Users\Mike\AppData\Local\Plex\ Media\ Server\Codecs\18f9bcf-1233-windows-i386\’ XDG_CACHE_HOME=‘C:\Users\Mike\AppData\Local\Plex Media Server\Cache’ XDG_DATA_HOME=‘C:\Program Files (x86)\Plex\Plex Media Server\Resources’ X_PLEX_TOKEN=‘xxxxxxxxxxxxxxxxxxxx’ C:\Program Files (x86)\Plex\Plex Media Server\PlexTranscoder.exe -noaccurate_seek -ignore_unknown -scan_all_pmts -1 -i http://192.168.1.2:5004/auto/v25.4?transcode=heavy -map 0:V? -codec:V copy -map 0:a? -codec:a copy -copypriorss:a 0 -map 0:s? -codec:s copy -segment_format mpegts -f ssegment -individual_header_trailer 0 -segment_time 1 -segment_start_number 0 -segment_copyts 1 -segment_time_delta 0.0625 -segment_list http://127.0.0.1:32400/video/:/transcode/session/34c0703b-370a-43fd-9033-815376ccbb01/1bacb5db-8a4e-4deb-824d-6ef8924b8881/seglist -segment_list_type csv -segment_list_size 2147483647 -max_delay 5000000 -avoid_negative_ts disabled -map_metadata -1 -map_chapters -1 media-%05d.ts -start_at_zero -copyts -vsync cfr -y -nostats -loglevel quiet -loglevel_plex error -progressurl http://127.0.0.1:32400/video/:/transcode/session/34c0703b-370a-43fd-9033-815376ccbb01/1bacb5db-8a4e-4deb-824d-6ef8924b8881/progress
Jun 08, 2017 12:30:01.138 [3844] DEBUG - EPG[onconnect]: Next thing to start/end is at 2017-06-08 17:00:00 (in 1800 seconds)
Jun 08, 2017 12:30:05.530 [7736] ERROR - [Transcoder] http://192.168.1.2:5004/auto/v25.4?transcode=heavy: Server returned 5XX Server Error reply
Jun 08, 2017 12:30:05.545 [5144] DEBUG - Jobs: ‘C:\Program Files (x86)\Plex\Plex Media Server\PlexTranscoder.exe’ exit code for process 8528 is 1
Jun 08, 2017 12:30:05.545 [8992] DEBUG - Using default transcode duration of 120 minutes
Jun 08, 2017 12:30:05.545 [8992] DEBUG - Started session successfully: 34c0703b-370a-43fd-9033-815376ccbb01
Jun 08, 2017 12:30:05.545 [8992] DEBUG - DVR:Recorder: It took 5.3 sec to start the session for http://192.168.1.2:5004/auto/v25.4?transcode=heavy
Jun 08, 2017 12:30:05.545 [8992] ERROR - Unable to find title for item of type 5
Jun 08, 2017 12:30:05.545 [8992] DEBUG - MDE: analyzing media item -1
Jun 08, 2017 12:30:05.545 [8992] ERROR - MDE: video has neither a video stream nor an audio stream
Jun 08, 2017 12:30:05.545 [8992] DEBUG - MDE: ignoring media item -1
Jun 08, 2017 12:30:05.545 [8992] ERROR - MDE: no compatible media decisions are available
Jun 08, 2017 12:30:05.545 [8992] ERROR - DVR:Recorder: Unable to compute media decision.
Jun 08, 2017 12:30:05.545 [8992] ERROR - DVR:Recorder: Error 14 starting the record, shutting things down.
Jun 08, 2017 12:30:05.545 [8992] DEBUG - DVR:Recorder: Asked to stop recording ‘The Best of the Joy of Painting - E1 - Gray Mountain’.
Jun 08, 2017 12:30:05.545 [8992] DEBUG - DVR:Recorder: Stopping transcode session.
Jun 08, 2017 12:30:05.545 [8992] DEBUG - Killing job.
Jun 08, 2017 12:30:05.545 [8992] DEBUG - Job was already killed, not killing again.
Jun 08, 2017 12:30:05.545 [8992] DEBUG - Stopping transcode session 34c0703b-370a-43fd-9033-815376ccbb01
Jun 08, 2017 12:30:05.545 [8992] DEBUG - DVR:Grabber: Freed a tuner (now 2 available)
Jun 08, 2017 12:30:05.545 [8992] DEBUG - DVR:Grabber: Operation for The Best of the Joy of Painting - E1 - Gray Mountain completed with status error (An unknown error occurred)
Jun 08, 2017 12:30:05.545 [8992] DEBUG - Activity: Ended activity dd7e1158-b113-4228-bf16-128a171cb4de.
Jun 08, 2017 12:30:05.545 [8992] ERROR - DVR:Grabber: Starting media grab failed.’
Looks like a record attempted to start at 12:30 “The Best of the Joy of Painting - E1 - Gray Mountain.” It then ended 5 seconds later when a 5XX error was returned from server which should be the HDHR.
What HDHR device do you have? Have you tried other Transcode settings? I would suggest turning off the Transcode setting in Plex and see if you can record something.