I have tried to create a pattern for a cover on a military hat. One piece is a circle. I create it as an arc from 0 to 360. In the draw mode, it looks good. However, I am unable to continue to the detail mode. When I use the seam allowance tool in draw mode, The "ok" option is greyed out and I can't complete the main path. The pattern piece should be a simple circle with a seam allowance. Is this a bug, or am I doing something wrong?