Unable to unstack blocks, and the Control + Click isn't working anymore.

Just loaded the latest version 1.6.1, and first thing I noticed is that the Button 2, which has also been Control + Click wasn't working. I couldn't get it to work it in the controls options. I'll make due with just using a different key. Then when I tried making things, I couldn't get the blocks to unstack with clicking on them, I've tried every key to get them to unstack but I don't know what else to try.