PROBLEM
When you are placing spot elevations sometimes you will get the no go simple on all your flat surfaces and it will only work on the edges of the object.
SOLUTION
All you need to do is change “Visual Style” from “Wireframe” to any of the other options.
Basically the spot elevation tool does not work unless the surface is visible.
In Wireframe model the surface it not visible so the spot elevation only works on the edges.
PROBLEM
You can't place a spot elevation on a Ramp (circle with line through appears).
SOLUTION
Place the spot elevation on a flat bit of ramp (i.e. landing) - it will say [no slope].
Then move it to a sloping part of the ramp.
NOTE: make sure you select the text - not the blue dot (the blue dot just move the text location, not the location of the tag itself).