I definitely recommend staying away from this bike at all costs. I was leaning in that direction from the beginning, and after finding out about the missing title I'm absolutely sure. You can't do anything with a bike with no title, even if it is fixable. And you could not sell the engine or frame, as they have numbers on them. Selling the frame would definitely require a title.
But, if you like the Ninja 250, and fit on it, it's a great bike. From experience I definitely recommend the '07 and older models. They are more comfortable, more solidly built (or at least the plastics are) they were around for 20+ years and are well proven, they have a real seat, and even a centerstand. They have no known issues. I recommend going up one tooth on the front sprocket, they are one of the very few bikes that really are undergeared from the factory. It's getting harder and harder to find a nice one, as they were mostly bought by beginners, and most of them were trashed. I had an '07 for a couple of years that I bought new. I was just to big for it. And I'm 53 and no beginner. But they are fun little bikes.