[ShotgunNinja]

How big is your program? It won't fit if it is too large. You may need to either downsize or optimize your code to make it fit. I'm thinking that this might be your problem, especially if you have, as you say, downloaded code to it several times in the past.

Also, you might want to try resetting the memory of the cRIO completely, then redownloading. Maybe some code fragments are clogging up the memory. But I really can't say either way, I haven't tried it out or researched into it enough yet.