Recently I started playing with FreeCAD. I tried some tutorials, made few my own models. From time to time it crashes, but I learned to save often, so it's not a big problem. Especially, that I use it for amateur, hobby things.
However, yesterday I faced a problem, that I can't cope with.
Problematic file is attached.
Now, I want to rebuild some part of "szkielet" sketch, so I double click it to enter edit mode. For some reasons, FreeCAD crashes at this step. Sometimes, but very rarely. When I enter edit mode, I want to delete constraints 107 and 108. When I do that, whole drawing tips over. I found out, that's because of constraint to external sketch "otwory" which, for some reason, changes angle to 180 degrees when I remove constraints in another sketch.
What is a reason for that behaviour? Is it wrong to edit sketch after other operations were made (like pad, or pocket)? Maybe I shouldn't attach "otwory" to pad face, which was made from another sketch depending on "otwory"?
Also, is pad supposed to update itself, when I alter sketch it is based on? I added an arc - element 56 in a sketch "szkielet", but as you can see in a file, part based on this sketch didn't reflect the altered sketch.
I use Part Design and Sketcher workbenches only.
This file was originally created in dev version 0.18.15188 on windows 10 x64. Reason for using unstable version is that, I had a similar problem in 0.17, and I wanted to try dev builds, as I thought, that there may be a bug, that's already fixed. I also tried that on another pc with windows 7 x64, with the same results.