Hi Jim, I haven't taken a close look at your model yet but one big thing to note is that it looks like there is not much space available in those areas that you are trying to fillet.

A fillet will not be successful if you ask for a radius that is too big to fit within the available space.

Sometimes it can be a bit surprising how much space fillets take up, especially since they can kind of eat away at pieces from both sides.

So because of that one thing to try in general when you run into a fillet problem is to reduce the radius that you're asking for and see what that does. For example try asking for a radius of 1/2 of what you did initially and then maybe even 1/10 as much.

- Michael