new error messag
I have an"refurbished" iMac that was purchased 4/4/13.
After installing the April 30, 2016 iMovie upgrade I cannot play videos, I now am getting an error message: the system extension"/System/Library/Extensions/ALF.Kext" was installed improperly and cannot be used. The only thing I did was your upgrade!
iMac, OS X El Capitan (10.11.4)