I am following this video
but my guides retain horizontal or vertical and don't rotate. When I activate
Rotate tool I can only move cyan rotation center, but can't rotate guides.
What can be done?
AI is 23.0.1
Make sure the giude you want to select is not locked, and active when you use the rotate tool. The active guide will be a different color than the non-active guides.
In my version of CS5 Illustrator I can check if guides are locked or not by going to the "View" menu, then navigating down to the "Guides" option.