Yes the 500 segment circle is probably the problem. If you are drawing this at the actual size you will be attempting to create geometry that is too small.
Sketchup has problems forming faces when the line segments go below 1mm.
Try scaling everything up by100 and reduce the number of segments in the circle, 500 is more than overkill.
There are quite a few ways to make simple bevels.
Here I have used offset to create the lines then moved the face up on the blue axis by taping the up arrow, you could also select both outer edges and move them down on the blue axis.
