"Crashing after a few seconds" - what exactly did you mean? Did the game completely crash out? Did it reset? What exactly happened?
There aren't any inherent places you shouldn't be able to transition to on the screen, unless by chance there is a warp tile that you collide with in that exact spot on the new screen (because then, you'll be colliding with it, and it'll automatically enact the warp...sending you back...and end up in an endless loop). You'll have to show me a video of exactly what you're doing and what you mean, as I'm a little lost. There can only be "one" warp tile per screen right now...because there's only "one" value to warp out to. You can PUT more warps on the screen, but you only have one warp-to value, so....all warps on a given screen will take you to whatever screen is in screen info.