"Failed to Converge" Error when drawing spiral curve between two fixed arcs, using Spiral between elements tool

Hi all,

I am trying to draw a spiral curve between two arcs.  One of the arcs is entirely inside of the other one.  The radii of the two arcs is only different by a couple of feet so I imagine the spiral connecting them won't be too long.

Here is an image showing the arcs - I need to connect them with a spiral and I am getting the error "Failed to Converge" when selecting equal constants and Clothoid.  Help on how to do this so the one arc spirals into the other one would be much appreciated. The spiral needs to increase or decrease in curvature linearly from the one curve radii to the other one.