My Illustrator has gone full bore wonky...

Hey all,

I have a job to do and I’m panicking. I updated my Mac Mini 2018 today with the new Sequoia 15.8.1 update. Shortly after, I launched Illustrator, and right in the middle of working on a map, drawing a bunch of roads, my black and white Selection arrow tools reversed their functions. Literally, right in the midst of working on my drawing...one minute things were fine and the next...crazy. Not only that, but my Pen tool won’t end a line now. I click once to create a point and click again to create a line, and it won’t let go...won’t stop at the last point. It wants me to keep drawing. The only way to let go is to hit Escape, or click back to the first point, which I cannot do. This is freaking me out because I can’t draw now. I’ve been working in this program since the late 1980’s. I’ve never seen it do anything like this.

I should add that I completely uninstalled Illustrator, removed my old Preferences, and reinstalled the program thinking maybe it became corrupted somehow. That didn’t fix a thing. What the heck? It’s still screwed up.

HELP!!!!