Application encounters a problem with video

I have been using LM for over a year. I used to get a downloaded movie every now and then that would lock up any application that tried to run it. Now every single movie I download does this. I can not even open MY Videos folder to see the files. the message I get is that (blank) has encountered a problen and needs to shut down. I am pretty sure these files are good because I downloaded VLC and you can open them through that. Though this does not help my dvd converter application. Also bitzi says these are good files. Please Help, I have not read a related thread about this,