Videos won't play in iphoto anymore

I noticed the other day a few videos that were on my iphone weren't on my phone anymore. I checked my iphoto library folders and they were still there, but would not sync to my phone. I tried to play the videos in iphoto but they do not play anymore! I get this error message: You may need to install additional software to open this type of file.

I don't understand why a few months ago they played in photo but now don't. I can't export the files either, I get an error message. I have all the latest updates.

Help!