In the What's New release notes for V6.3.39 it says: * Change the ARC interaction logic, keep the center of the circle unchanged when edit the start/end point; Adjust the properties panel properties options In V6.3.22, I used the Arc tools to easily create accurate rounded ends to a rectangular cutout. I could do this because I could independently specify: * the start XY coordinates; * the end XY coordinates; * the centre point of the circle on which the arc lay; * the radius I could also specify clockwise or anticlockwise direction that allowed inside or outside segments of the arc to be created I could also specify the start and end angles of the arc with respect to the centre of the circle on which it lay. With V6.2.39 I cannot independently specify the start XY coordinates and the end XY coordinates. Now there is only the option to specify the start and end angles of the arc with respect to the centre of the circle on which it lay which means that if I change the radius, the start XY coordinates and the end XY coordinates change. Most people do not think in terms of Polar Coordinates and the Canvas does not support them anyway so unless I do some very complex trigonometry to work out where the start XY coordinates and the end XY coordinates are going to be given the centre, the radius and the start and end angles, it is no longer possible to accurately position an arc of a defined radius. I can do the same job by editing the points and Arc segments in the Solid Region tool but I particularly wanted to use the Arc tools to create a shape directly in the Board Outline since in one particular application in a PCB Footprint, the Solid Region set to No Solid was giving multiple DRC errors and I suspected that creating the same shape using a Board Outline directly would not. Please reinstate the Arc tools functionality of V6.3.22 or add a switch to allow different modes of use. Thanks.