I hate to be the one who has to tell you this, but this is how to fix it:
Open our world.ini
find your entry 'climb left strip'
click to place your cursor after the '1' that you set it to. press right. That' right, there's a <tab> there, and it's screwing the ini up. once you remove it, the game won't give that error.
(so you don't have to bother, i've attached a fixed ini (it's in txt format, just rename it))
Also, don't forget to set the rest of the values that you haven't yet, such as width and height. without those, all you'll see is a grey window