Slab edge not conforming to edge

[cbt990]

This worked for me before. Why won't the slab edge move with the floor?

[cbt990]

Any ideas anybody? Still can't get this to work again.

[barthbradley]

Why not use a slope arrow instead of Modify Sub-Elements? 

...or are you wanting the Slab Edge to change height as it follows the slope?  If so, Model the Slab Edge as a Wall and use Attach Top/Base Tool. 

[cbt990]

I tried modeling using slope arrow. Still can't select an edge for slab edge.

[barthbradley · Accepted solution]

Slab Edge first, then Slope Arrow second.