I noted several video start and immediately stop, while in iPhoto app these files played right. These files are all .3gp
When I upgraded from Mavericks to Yosemite (iPhoto to Photo) something happened?
MacBook Pro with Retina display, OS X Yosemite (10.10.4)
Upgrade to 10.10.5 as that fixes some GoPro compatibility issue: OS X Yosemite 10.10.5 Combo Update
I have latest version 10.10.5
Try applying it again. It can't hurt and might do some good. Also repair disk permissions afterward.
I followed your suggestions but with no results.
Are you able to play those files with Quicktime Player outside of the library?
No, I am not able to play it by Quicktime. I tried successfully by VLC.
What format did you export it out of Photos with?
from iPhoto to Photos
