Keep getting an error every time I trim a video clip?

Hello I am using Windows Live Movie Maker and I editing home movies so I can use them for a video I am creating. The clips are a .VOB file and I insert them in the Windows Live Movie Maker and when I go to use the trim tool I keep getting this error: 0x87160139. And what is the strangest part that earlier this week like Monday through yesterday I was able to trim these clips with no problem. Please help and thank you!