I'm almost embarrassed to ask this, but I'm having trouble adding a simple fillet. I was able to add a similar fillet to the opposite side of the part. I get the 'radius too large' error when I try to add it. Needs to be R.125" like the other one. The attached picture shows which edge I'm having trouble adding the fillet too. I'm stumped because the edges are very nearly identical and the fillet works on one side of the part and not the other. Help, please!