I use inverted mouse controls (Left place, Right Attack), so I try to click with my left mouse button, although it won't work! The mouse works with other programs, also when I try to click with the left mouse button on Minecraft, there's a chance it will work, or it won't. I'm confused whats going on, if you need additional info, just ask. (Btw I use a laptop's mousepad.)
Left Mouse Button not Responding to Minecraft