12:21 <gregor3005> I created a box, when I add another extrusion inside it gives me this: https://i.imgur.com/weujPuJ.png

12:22 <gregor3005> There are no degrees of freedom, so all points have constraints. The constraints are not overlapping. How can I debug/solve this problem?

12:25 <gregor3005> The new element is colored in green

12:30 <gregor3005> When I delete the element the red warnings didn't disappear. Reopen the file redraws the object without the red lines

12:47 <gregor3005> Replacing the arc with an circle resolves the problem, the design is now different but its no problem

15:19 <whitequark> gregor3005: try clicking on the group name and ticking "force NURBS surfaces to triangle mesh"