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Jethro!

macrumors 6502
Original poster
Oct 4, 2015
330
341
HS 10.13.2. Trying to make QuickTime Player the default app to open .mov and .mp4 files, but I can't make this preference "stick". e.g. Opening "Get Info" for an .mp4 file, I change "Open with:" to QT Player, check "Always Open With", confirm, click "Change All..." in the Info window to make sure, confirm, and that should do it. And it does, until after a restart/reboot or two, then it reverts back to another strange app for its default.

Looks like a HS bug. Can anyone confirm?
 

jbarley

macrumors 601
Jul 1, 2006
4,023
1,895
Vancouver Island
HS 10.13.2. Trying to make QuickTime Player the default app to open .mov and .mp4 files, but I can't make this preference "stick". e.g. Opening "Get Info" for an .mp4 file, I change "Open with:" to QT Player, check "Always Open With", confirm, click "Change All..." in the Info window to make sure, confirm, and that should do it. And it does, until after a restart/reboot or two, then it reverts back to another strange app for its default.

Looks like a HS bug. Can anyone confirm?
I can confirm it's not a bug on my High Sierra install, Quicktime is the default player with no input from me.
Just which other "strange app" are you referring to?
 

Jethro!

macrumors 6502
Original poster
Oct 4, 2015
330
341
I can confirm it's not a bug on my High Sierra install, Quicktime is the default player with no input from me.
Just which other "strange app" are you referring to?
One type insists on being opened by Tagger (mp3 metadata editor) and the other by MPEG Streamclip. I should be able to change the default associated apps, and I can, it just doesn't "stick" permanently.
 

jbarley

macrumors 601
Jul 1, 2006
4,023
1,895
Vancouver Island
Maybe try and rebuild the "LaunchServices database", any of several methods can be used.
Probably the easiest is to run Onyx Maintenance with LaunchServices selected.
In fact it wouldn't hurt to run the whole Maintenance package, never know it just might clear out a rogue cache file.
 
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monokakata

macrumors 68020
May 8, 2008
2,063
605
Ithaca, NY
I had this same problem Amadeus Pro (an audio app) always tried to open mp4 files.

I wasn't able to fix it until I ran into something on the Adobe forums (I think; I forget).

Start your Mac in Safe Mode, let it boot up, log in as yourself, then shut down.

In my case, that solved the problem completely.
 
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jbarley

macrumors 601
Jul 1, 2006
4,023
1,895
Vancouver Island
I had this same problem Amadus Pro (an audio app) always tried to open mp4 files.

I wasn't able to fix it until I ran into something on the Adobe forums (I think; I forget).

Start your Mac in Safe Mode, let it boot up, log in as yourself, then shut down.

In my case, that solved the problem completely.
That figures, one of the things starting in "Safe Mode" does is clear some caches.
 
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