Opening grips disappear

[Mike Sealander]

Without rhyme or reason, the horizontal grips for a rectangular opening in a wall sometimes disappear after I try to modify the opening. Why?

[D_Driver]

can't tell you why, but now I have seen it myself
looking for a clue.
has nothing to do with the view settings, older openings. grips are gone. new openings, grips are there.

[gbrowne]

Graphic card issue? Does your display ever go a bit wonky?

[antman]

I've had this issue on multiple computers, new and old, some with no other oddities of note. I shy away from the opening tool now, and just use an empty door family.