I tried taking the file and importing it in Fusion 360 - it still wouldn't fillet.

I tried getting the point count on both the circle and rounded square to be the same - still didn't work. I've been trying it for hours, multiple different shapes, trying rounded squares, nothing seems to work. For some reason though this doesn't seem to be possible. I've been trying to model a computer stand and there is a transition going from round to square and I've tried every possible way I could think of to get this to work, the most direct being to just loft from a cylinder to a square and fillet the transition. I also found out that different applications handle fillets differently, so one app might be able to do something that another would not. I've read on the forum that fillets can be quite tricky and that there are workarounds when a fillet won't calculate. I've been racking my brain with fillets for the last 2 days. I'm new to Moi, and CAD for that matter, and have been giving myself some basic modeling exercises to pick up the program and the concepts of CAD.

Loft fusion 360