Thinking out loud here - any chance it’s somehow associated with the fact that my previously working plexignore files no longer work? At first glance, it appears that Plex isn’t ignoring things it’s supposed to in both cases…
I see they might have a fix ready for the plexignore problem.
I think that is rather unlikely.
Local Extras work perfect for me. But I only use files without internal metadata.
Do you still happen to have the local media log?
@OttoKerner - I’m 99.9% sure the only metadata in the mp4’s is the tag for language - I make sure there is no embedded metadata to screw up the scanners. Are you suggesting the language tags are the problem? I can add another movie as an MKV and remove those tags as an experiment, but I can resolve the problem by disabling the partial scan option.
I’ll get back to you in a couple of minutes with a bare bones mkv trial
I imagine you are referring to this one:
com.plexapp.agents.localmedia.log
If so, it is attached.
Did you add the trailer file after the initial scan? This is what I see from the localmedia log.
11:56 - Initial scan finds the movie and the 2 subs but no trailer. It doesn’t even mention the “Trailer” folder.
11:58 - Another scan, this time it sees the “Trailer” folder but does not find a trailer file. It thinks the file is a movie for some reason.
12:10 - This scan sees the “Trailer” folder and properly sees the file inside as a trailer and adds it as such.
12:13 - Another scan and it can’t identify the file as a trailer and adds it back as a movie, similar to the 11:58 scan.
In my tests I only get the 1 scan that works properly, so I’m not sure what is going on. Can you find the scanner log(s) for the time periods above.
I just copied the entire folder from the kids movie section to the movies section, so I can’t tell you how Windows handled that operation. But not one file at a time, if that is what you are asking.
Tries adding a stripped down mkv - same results. I didn’t need to refresh this time to see the trailer on the pre-play screen, and it also shows a second trailer, downloaded as an extra.
So much for that theory. 
Are there tags in the trailer file? Plex is picking up a title from somewhere.
title=“Trailers”
I guess this comes from the containing folder. Plex doesn’t read metadata from MKV files.
Ah yes. Forgot about that. Ok. I need the scanner logs.
Sorry, I couldn’t seem to find a log file with the time stamps you asked for, probably because I added the Wall-e movie as an experiment… But I have attached as many logs possible for the scan of Wall-e. Hope it helps, and at least two of them are the right file and line up with each other
I’d like to get rid of the fake files and movies. No critical, but do you think you will need more info at a later time? If so, I will leave them as is for now
No, I think I have all I need. It does appear to be a bug with the partial scan. Not sure why I’m not see the problem on my end. Basically your scanner, when it sees the file being added to the “Trailers” folder is treating “Trailers” as the name of a movie folder and not as a subset of the underlying movie. When going to the preplay screen, the local media agent kicks in to then scan the file as a trailer, but that doesn’t get rid of the improperly matched “Trailer” movie.
Is your L drive internal, external or networked? Mine are internal and wondering if that makes a difference.
The L drive is an external USB drive. I will try adding a movie to the internal drive to see if that is the problem
EDIT: Nope - Same thing with the internal drive. Worth making sure though
