Middle mouse button will not paste

I have a Logitech M560 mouse, but I do not know how to map the middle button to pasting, as is default in my other mouse.

I ran 'xev' and clicked the middle button in the white box. The output includes 'button 1'. So, I want to map button 1 to the 'paste selection' as clicking the right and left mouse buttons simultaneously does with my mouse now.

I had the same issue today (2016-08-29). It is unclear what caused it since I didn't upgrade anything in the past 4 days.

Rebooting didn't help.

Key observation: xev wasn't showing any event coming from the mouse when clicking the middle mouse button (scrollwheel) inside the xev little square. This indicated some low-level driver issue as opposed to an application config issue.

Mouse selection was working fine: clicking Shift+Insert or running xsel from a terminal were both pasting the current selection.

Only the pasting via the middle mouse button didn't work. The problem affected all applications, including firefox and terminals.

Eventually, this fixed it for me.

sudo dpkg-reconfigure xorg