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.
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I did try that first, searching, but I didn't find anything, and that problem doesn't look resolved either, just that maybe it'll be fixed in the next version. Also that ticket was about the right click thing, I can deal with that, the not being able to unstack I cannot deal with. That problem is too broken to play the game right now.

Touchscreen mode enabled ? Check Game Menu -> Options -> Touchscreen mode
Touchscreen mode is off.
Duplicate of MC-13695, please use the search function to see if your bug has already been submitted. Currently over 58% of tickets are being closed as duplicate.