Dropped Frames Warning

I am using FInal Cut Pro 7 in OSX Yosemite and I keep getting this message when I try to play through cross dissolves. It was working just fine and then my canvas went black. After checking that it was set to Image and RGB, I trashed the preferences and now I have this new problem. Screen Shot 2016-04-15 at 20.01.41.png Does anyone know why my movie won't play through these?
file:///Users/fanny/Desktop/Screen%20Shot%202016-04-15%20at%2020.01.41.png

hi, that pic didn't work. you'll need to upload it to a picture hosting site.
a lot of folks here use photobucket.


nick