Just want to add my experience to previous topic with same title: my Acer Chromebook 14 also cannot alt-drag to draw circles. I'm using a mouse. I tried left and right ALT keys. What is DOES do is interesting: when you hold ALT, and drag with left mouse button, you see nothing but a moving mouse pointer. Then, when you release the left mouse button, you get a context menu, as if you had pressed right mouse button. Generally speaking, across all of Roll20 (so far that I've seen) combinations of ALT and mouse drag malfunction. I'd also like to observe that Chromebook and Roll20 are both web-centric ideas, and seem like a natural fit together.
