Beginner’s help

Hi all. Can anyone help please with the following newbie issues.

1-I’ve uploaded loads of video files to my NAS and mp4 and avi etc all seem to be playing ok, however, I’ve added all series of “the inbetweeners” which via the NAS I can see are all in the folder but when I go to the “films” section where they are stored Plex doesn’t see them. I’ve got regular scanning set and other movies etc are visible/playable. I’ve also just uploaded “the office US” all series and the same has happened.

2-I’ve got quite a few duplicate movies appearing on the Plex menu, although when I check the file folder there are no duplicates as I’ve deleted the ones that were.

3-lastly I’m struggling to try and get apps into Plex like stv player/itv player/bbc iPlayer and I’ve researched as best as possible.

Many thanks in advance for any responses/help

re #1/ you best separate movies and tv-shows into their own top level folders. Plex won’t mix them and will ignore files that are named like a tv-episode in a movie library.
https://support.plex.tv/articles/naming-and-organizing-your-tv-show-files/

re #2/ when you add files to Plex, it’ll attempt to match them. That means it’ll try to figure out what movie they are and load the related metadata, posters etc. – if your file names are off / ambiguous, Plex will sometimes fail to match them correctly and can consider different files to be linked to the same movie. The same is true if you have different quality versions of the same movie.

Generally you should be able to use the Split Apart option for those duplicates and subsequently Fix Match for the one that’s actually a different movie.
In the long run it’ll be helpful if you can stick to the official naming schema to avoid such incorrect duplicates in the first place
https://support.plex.tv/articles/naming-and-organizing-your-movie-media-files/

re #3/ Plex has stopped supporting plug-ins that allowed direct integration of other apps / streaming platforms into their environment back in 2018. You can use Plex’ Discover feature to see where certain movies are available; some platforms will allow you to click on a movie and jump to the respective app.
https://support.plex.tv/articles/discover/