I've selected RULERS, TOOLTIPS, SHOW GUIDES, SNAP TO GUIDES, SHOW SMART GUIDES, and SNAP TO SMART GUIDES.
I click on the ruler and drag a guide to the place where I want the guide to be and as soon as I release the mouse button the guide disappears. What am I doing wrong?
Make sure you are dragging from an area of the ruler directly above or to the left of the canvas area. Otherwise, as you have observed, the guideline will not set.
Thanks. It takes a bit of practice, particularly with a horizontal guide, but I'm finally able to do it.