Paper2d Pt.4

I feel that there was a great deal of accomplishments made in this last paper2d tutorial, but I feel something is missing, or I’ve missed something in the ladder section. I can’t get my character to stop on top of the plane, but before I even get that far I can’t get my ray from the LineTraceByChannel. My problem is (and correct me if this was covered in the video) I don’t know when to call the custom event for DetectLadder. I’ve tried running it through OnCollision, and casting to BP_Dude, but nothing seems to be working correctly for me. I’ve looked through all of the screen shots, and spent almost 14 hours going over just this section, and can’t seem to find where we are calling DetectLadder. Is there any way someone could point me in the right direction?