I suspect one aspect of the problem may be that one of the lines coming into the corner is an arc, not a straight edge. Depending on which tool you use to draw the arc and where you start the arc, this can confuse the tool because it can’t figure out where the end of the arc is supposed to be. The ends of segments in that arc are not necessarily at radius 1/4 from the desired center! Here is an example using the simple Arc tool after setting the number of sides to 8. Note that after clicking the center at the guide offset 1/4 from the straight edge, I use a red inference to find the start point on that edge. Then I swing the arc until I see a magenta inference that the arc is ending on the other curve.
It’s also worth knowing about the Magenta Inference with the 2 Point Arc tool.
Yes it will also give you the silly error if you use too many edges, but it does actually adjust if it only needs to remove 1 or 2 to make it work.
Start your arc and move along the other edge until you get a magenta arc, click once, move back along that edge until you get the magenta arc again, don’t click, let go of the mouse and type 1/4 and hit enter. The arc will adjust to a 1/4 radius, and if needed it will remove a segment.
The addition of the message and segment limitation was introduced by request of users who model small items for 3D printing to help them avoid creating geometry that results in non-solid groups and components.
