How to I have my enemies actually look for the exit?

Dear all,

I'm quite new but I love C3 and the all community! Let me thank you for the help in advance. I'm doing a tower defense and I've built the logics around the enemy and my "End". The game is that you have a blank background and you can build blocks and turrets on it, the enemies once you've created those should recalculate their path and follow it but my enemies just hit the blocks and scratch until morning.

This is my Event page:

and a screenshot of what happens:

Any suggestions?

A simple use of pathfinding: dropbox.com/s/fumc7ctko35r68r/tap%20path.capx

Thank you!