I had the same problem, but was able to fix it by loading the exact .cr2 of the figure I was creating a walk for. As soon as I did that, the walk designer started working again, except for when I change the path, and reapply, the figure still follows the same path as the first one I assigned. It will change the style of the walk and reapply, provided it has at least as many frames as the first one. Do you have this other issue as well, or does the fix CL reported work on this also?