Trying to create a still image from a video clip and keep getting a "general error" message.

I'm trying to create a still image from a video clip but I keep getting a "general error" message when I try to do it. The clip has a lot of layers to it and it appears as if it's the upper most layer that's causing the problem. The layer contains text, and only text. If I remove that layer from the clip, no error message. The thing is, not only are there several other layers of text in the clip that don't cause any problems, I can put a different layer of text in the same spot and not get that error. All of the text layers were created in the viewer. I did nothing different (that I'm aware of) in creating the problem layer.