Check for missing thumbnails and artwork.

[srazer]

Sometimes the artwork and thumbnail in the Plex metadata vanishes. Check to see if all thumbnail and artwork point to valid URLs/pictures.

https://forums.plex.tv/index.php/topic/95148-rel-findmissing-files/?p=558139

https://forums.plex.tv/index.php/topic/87206-feature-request-re-create-missing-media-plex-objectsinfo/?hl=recreate