Hi gizmo - it seems to be filleting ok over here, here is a screenshot of your pad2 file filleted with a radius of 1:



My guess would be that you're running into one of 2 things.

First - in the file you posted there is an additional curve object on top of your solid, overlapping the edges. Curve objects take selection precedence, so that curve may be interfering with the selection of edges of the solid. Try selecting the curve first and then delete or hide it to get it out of the way so that you can more easily select parts of the solid. But you can actually just select the whole solid in this case instead of selecting any edges at all.

Second - what fillet radius are you using? As you can see from my screenshot a fillet of radius 1 fills up quite a bit of the area there, there isn't much room to go to a radius too much larger than that. If you are trying to use a larger radius then that could also be your problem.

I hope that this may help to solve your fillet issue, please let me know if you still can't get a fillet there even after taking these 2 issues above into account.

- Michael