I'm running PMS in MacOS Sierra on a dedicated Mac mini Server and have formerly been using iTunes to supply media to the whole house. I now think Plex can do a better job and am trying to effect the transition. But some issues.
First of all, iTunes has been (and will be for the foreseeable future) used to tag the media files. Everything I have in iTunes is correctly identified and iTunes of course ensures that the embedded tags are kept in sync with what data has been entered. I have it set to 'Keep Media folder organised' which means it names the files and places them in its predetermined structure which is in fact very sensible folder structure of varying depth, according to the media type being stored. But this cannot be changed. iTunes does what it does and the user just has to live with that. On the whole this is not a problem as it gets it right, but there are glaring holes in this eco system, most especially, no actual server or ability to be run as one. This where Plex comes in.
PMS is all set up and I created a Movies library and pointed it at iTunes' Movies folder (most media type names are the same in both products). It was surprisingly slow, but it did eventually finish and has the exact same number of items as iTunes reports. So without checking further, it looks like everything is good.
I then set up another movies type Library and pointed at a folder of non-commercial videos. None of these would be found on IMDB etc. Not many in total, so didn't take long and then I had a list of all the videos with nice poster artwork showing, presumably frames taken from the videos themselves and not the same as iTunes displays, but no problem, all is good.
After that I created a TV Shows type Library which basically worked. Some issues to sort, but at least it obviously found all the files, even at different levels within the folder to which the Library was pointed.
Then I wanted to add some other videos of TV Show type, but for which I don't expect any metadata to be found on-line, so I created another TV-Show type Library and pointed it at the appropriate folder. One of the items is in a 3 level heirarchy of Show/Season/Episodes, the other 3 of them are simply Show/episode(s). As a matter of interest, iTunes will not bother with the Season level if there is no Season specified. Hence its TV Shows media folder can contain a mix of folder structures with different levels. But once scanning was complete, this library was empty and remains so.
At first, I suspected that varying levels of folder structure cannot exist in the same Library, but the main TV Shows Library does contain such, as created by iTunes due to the existence or not of any seasons and they have been imported ok by Plex. But this other TV Shows type Library fails to find ANYTHING.
So this is the main problem. I don't care a rat's ar** what the folder structure is or is not, nor what the file is called. It WILL be something sensible created by iTunes. The fact is that all the important and correct information is contained within the files' embedded tags. So the first thing I want Plex to do is find ANY suitable files (video in this case and all either MP4 or M4V or MKV) at ANY level in the folder to which it has been pointed, read the embedded tags and 'import' that into its database and then add anything else that it finds on the 'Net and that doesn't conflict with the embedded data (more on that later). Yes I know about Agents etc and 'Personal Media Shows' is the selected Agent and 'Local Media Assets (TV)' is selected and at the top of the list. I've deleted the Library (easy decision as there's nothing in it) and created it again, but whereas when creating the main Movies and TV Shows Libraries, it reported each file as it checked. For this Library I see no such checking the screen just immediately changes to an empty Library display, i.e. largely blank.
So the big question here is why this Library is not being created correctly. As far as I can tell, it should find all the MP4 video files and add them to its database using the embedded metadata (all I actually need), whatever the folder structure and naming. I don't want it to concern itself with folder and file names. All the metadata required is embedded in the actual files and should be used. Isn't that what ' 'Local Media Assets (TV)' is supposed to do. Why is Plex struggling with something so simple. iTunes may have its issues, but any fully tagged media file I throw at it gets perfectly imported with all that data then in its database. Can anyone please explain why Plex seems incapable of doing this.