I did update the cap but noticed yours was saved in an earlier version so here's some code instead (only replace the collision event, I only added the private variable test so you could recognise where I mean)....
Replace...
On collision between enemy1 and terrain
enemy1: Value 'Right' Equal to 1
On collision between enemy1 and terrain
enemy1: Value 'Left' Equal to 1
WITH
enemy1: overlaps Terrain : offset(2,0)
enemy1: Value 'Right' Equal to 1
enemy1: overlaps Terrain : offset(-2,0)
enemy1: Value 'Left' Equal to 1