Problem Rendering Animation

I can render once and then if I try a second time, it just hangs with checkerboard pattern in the display area. If I render image just one frame it hangs with a checkerboard and does nothing. If I render animation I get however many images there are for frames but all just black.

Anybody know what’s wrong?

thanks

Easiest way for us to see whats going on is to post a example blend file.

What OS, drivers do you have ? Do you render on GPU ?