Years ago I used Ideas cad software, and in that software sketches tended to blow up if you made changes to the history tree.  In Solidworks, I was pleased that sketches tended to be more stable.  NO MORE!  If you change a sketch plane, it's likely that the sketch will blow up.  If you even change the direction of an extrude, the sketch may blow up!  I will attach a photo of a sketch that blew up just because the direction of the extrude was changed.  ALSO, when you attempt to fix one of these sketches, weird things happen, like lines try to snap far away from where you may try to end them, and other odd behavior.

SO, here's another step backwards in this software.  Now we have half colored and half blue icons, and sketches that blow up.