I deleted the video preview thumbnails to save space but I have since clicked the button to add as a scheduled task, but it only adds when new movies are added. I made sure it’s not on scheduled task when added but on scheduled task. Any thoughts
It will do newly added movies first, so if you have a slow system and a lot of newly added items, it will take some time to get to an old movie.
There are 2 ways I can think of to force the generation for a specific item.
1 - Use the command line. https://support.plex.tv/hc/en-us/articles/201242707-Plex-Media-Scanner-via-Command-Line
2 - (Untested but should work) create a new library that only points to that 1 movie. Have that library set to generate index files. Turn off for all other libraries. It should now work on that 1 movie. When done, the movie in the original library should see the new index file as well.
Video preview thumbnails must be allowed for the particular library.
Go to the preplay page of that particular movie.
on the left side, click on the ellipsis ( . . . ), then ‘Analyze’.
Ok, 3 ways. 
@MovieFan.Plex said:
It will do newly added movies first, so if you have a slow system and a lot of newly added items, it will take some time to get to an old movie.There are 2 ways I can think of to force the generation for a specific item.
1 - Use the command line. https://support.plex.tv/hc/en-us/articles/201242707-Plex-Media-Scanner-via-Command-Line
2 - (Untested but should work) create a new library that only points to that 1 movie. Have that library set to generate index files. Turn off for all other libraries. It should now work on that 1 movie. When done, the movie in the original library should see the new index file as well.
I didn’t think about timing. Say i have a descent computer (2012 i7 quad core mac mini) what is your best guess how long it will take per movie? are we talking 10 min or 2 hours
@OttoKerner said:
Video preview thumbnails must be allowed for the particular library.Go to the preplay page of that particular movie.
on the left side, click on the ellipsis ( . . . ), then ‘Analyze’.
will the same work if instead of going under each movie and hitting analyze i just go under movies category and hit analyze
@Wpcrumbley said:
will the same work if instead of going under each movie and hitting analyze i just go under movies category and hit analyze
I think not.
@Wpcrumbley said:
I didn’t think about timing. Say i have a descent computer (2012 i7 quad core mac mini) what is your best guess how long it will take per movie? are we talking 10 min or 2 hours
Depends also on the resolution and bitrate of your movie files. a ~90minute 8mbps h.264 movie is right in the 10 minute area for preview generation.
Just try it out with my method. You only need to keep an eye on your cpu load (or an ear on your cpu fan 
)
