I've got a slime trail and I don't know why.

[Alumae]

https://www.dropbox.com/s/gmsbvst3luxbk0j/help.zip?dl=0

The linedef seems to be identical to all the others except when the game is actually being played. I'm using Zone Builder. Anyone know how to fix this?

 

[Boinciel]

Looks like a random nodesbuilder error - not sure what's causing it other than a freak accident of geometry.

Just change the angles of the linedefs in the area a bit if this happens again - I moved this one vertex and it seemed to be fixed.