I suspect that it’s a tiny-geometry issue.
E.G. things fail when <1/1000" apart…
Try making a copy of the part in question off to one side - as a component - Scale that copy up by say x100, then run the plugin within an edit of that copy - remembering to increase the radius etc by x100 too.
this time the 'rounding may well work.
Exit the edit and the normal sized version should now also show the successful rounding.
Delete the scaled copy.
Also, component modeling is useful in hard surface modeling. In some cases, you can even overlap components without merging the geometry. This makes things less complicated. Even if your end goal is a solid component, keeping details as groups and components is non-destructive, unlike intersecting & merging geometry.
I didn’t think of that method to start from. that’s good steps by steps to get the right shape. I’ll keep that in mind for modelling in the future.
Ok, I tried the method above. and it works for me. I can see what went wrong and I fixed it. then I used the round corner. it was perfect!
I can tell you that the artisan organic toolset is not free. it’s a commercial plugin. and the message i am quoting above. yeah all of them are not together. I keep them separate. for example, Knob component is a component. if I want to make one change to the knob. and the rest of the knob will get the same change. we both know how it works.