Stuck in DMP2013

Hey guys. I am currently stuck in map14 of DMP2013(zdoom maps). At some point in the map you arrive in a cavey area with a button that can be pressed multiple times and appears to do nothing. All other passages are either dead-ends or require keys. What am I supposed to do...?

That map is bugged and will be updated, here's the updated version of map14 zdoom: http://www.mediafire.com/download/xxhmiei519p823f/End+of+Days+-+ZDoom.wad

Thanks a lot TimeOfDeath!