I spotted this by chance - thought my model was finished but then noticed a rectangular hole pattern had collapsed onto a line. There were no warning messages; fortunately I spotted it before water-jet cutting the sheet.
Looking back to an earlier version, the sketch pattern looks OK but the slightest change to any dimension causes it to collapse (I guess it forces a recalculation). If I redefine the directions the pattern behaves properly again.
I'm glad I noticed it but really (a) it should never have happened in the first place and (b) the sketch should have shown a warning that the directions needed redefining.
