Hi Jim, those sharp corners can be difficult to fillet.

What fillet radius are you trying to use there? It looks like there is not much space available, so you'll probably have to use a pretty small value for it to have a chance to fit in that small space.

Also are you selecting just the outermost edges, or also the ones that are sinking downwards as well, you might try that as doing those inwards edges can help to make better rounded corners where things meet.

Also can you please post the 3DM model file so that I can take a look at the actual model and give you some more specific recommendations? It's hard to know for sure what will work just by looking at a screenshot. If you can post the model file as well that helps a lot to be able to look at things and give you some better advice.

- Michael