[1.2.2] CTRL-Z undo in VAB has no effect?

[MilkSage]

When in VAB, I have had mis-clicks that resulted in picking up and moving a part unintentionally, and I cannot cancel the move or undo the move, resulting in having to start over.

If I have accidentally picked up a part for move that I don't want to disturb, what should I do?  In the past, I believe CTRL-Z resulted in the part re-appearing in the original location, with a copy still on my mouse cursor, which I then throw away by clicking in the left-side parts panel.  However, recently I noticed that CTRL-Z has no effect.

I use KSP 1.2.2 on Win10, with SMURFF, MJ, ETO.

[Gargamel]

First off, confirm that Ctrl-Z has no effect.  Start a new build, add a command module, add a fuel tank.  Remove the fuel tank.  Try Ctrl-Z. 

If it does work, then that means there was another small step you did after your big whoopsie.  Something tiny you did became the last Undo-able action.  Your big move that wrecked your ship is no longer 'in the buffer'.  Time to rebuild.  I've done it, we've all done it.   Learn to save often and early. 

If it doesn't work, then there is an issue with your install, some where.  At the top of the forum here is a link on how to get support, post the log files as described and maybe somebody can figure it out.