I have an issue - I tried to play an m4v format video but this appears after I tried to open the video with Quicktime Player as my recommended app (but it was working fine earlier).
I'm not sure if I did anything but I'll describe what I did previously:
- A couple of days ago, when I selected any of my m4v videos, quicktime player would automatically open up and I'll be able to play my videos.
- However, I have another video that uses an "flv" format video and that can't be played using quicktime (I installed VLC player).
- After the installation of the VLC player, I'm unable to play my m4v videos.
Any advice?
As the modal message indicates, whatever you are doing is causing your system to try and open an app downloaded from an "unidentified" developer while your current "Security & Privacy > General" System Preferences setting only allows you to open apps downloaded from the Mac App Store and identified developers. I suspect your recent activities may have inadvertently changed your "open with" object class setting for your M4V files.
You can either check the "open with" object class association in the Finder "Get Info" or Context Menu window and change it if necessary or change the "System Preferences > General > Allow apps downloaded from:" option from "Mac App Store and identified developers" to "Anywhere" to prevent the modal message from being displayed and thus allow the offending app to open normally and either play the M4V file or provide a secondary error message indicating the offending app cannot play the M4V file. In either case, you can then associate the M4V object class back to the iTunes default app setting or the QT player of your choice.