Cursor disappears

I was running full screen mode and my antivirus window popped up and minimized the game. When I alt tabbed back into game, the cursor disappeared. I was able to exit the game by hitting escape and moving my mouse around until I saw the exit button highlight.

When I alt+tab out of the game then return, sometimes the cursor is missing.

I have found right clicking once or twice makes the cursor reappear on the screen.

maybe double-tapping "c" (combat mode) could help too.