I must've pushed some button or checked some box because solidworks doesn't show sketches after you exit from them. Sketches aren't hided or supressed, but still they seem to disappear. It's only in this file, when I open a new file everything works normally. I recorded a short video where you can see the problem. https://www.youtube.com/watch?v=Z1O-fCqOfXM&feature=youtu.be