Jason Burkett

I think I just found a way around it. I started the game and went into the controls. I switched the "pick block" function from "Button 2" (right mouse) to "`" (on my keyboard this is the button just to the left of the 1). After that the rght mouse button began to behave normally. The "`" button does not control the pick block function; the right mouse button does. I'll update this if anything changes.

I am experiencing the same problem. I have deleted worlds and created new ones and cannot solve the problem. I have also found at least one other person on this site experiencing this. I cannot split items in my inventory. The porblem is the same whether I'm in my inventory or using a workbench.