Option/alt+click on anchor doesn't work. It used to make anchor points to curve OR corner. It even says "Pen: Make Corner" at the bottom of the window in the "current tool" field, but actually it just creates NEW PATH.
And the Anchor point tool icon changes to "Pen tool - start path" icon on hover.

So you've actually managed to broke the most essential feature of Illustrator - which is to draw and modify vectors. Awesome job!

It would be actually rather funny if it wasn't COSTING ME MONEY THE WHOLE TIME FOR F*CKS SAKE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

FIX IT!