Sometimes, when I launch Minecraft (I am using Mac OS X 10.11.6) all the Minecraft menu buttons and also gameplay now requires double-click.

For example: To access Multiplayer I need to click to times(double-click), same for other buttons.

Changing Key buttons in "Controls", is impossible, you can choose only Middle Right or Left Button and even slider needs a double click.

When playing (you can't play).After spawning in the world you can just break blocks (using a double-click), BUT movement-impossible, inventory-impossible to open,jumping-impossible.