It seems like ZBrush locks up when I hit the Best Render option. I’m wondering if this is a known bug?
I have my antialiasing turned to 1.
I have shadows off.
I can click on some things, but when I try click on any of the top menu options, it will not let me… 
The only thing I can do is restart.
Known bug? We need some more information such as OS being used and your ZBrush version.
I’m using Windows 8.1.
Runnning ZBrush 4R6.
I’m making a tiling 2048x2048 texture with two separate layers.
It seems like when I hit the best option, it will lock up my top menu buttons. Like I’m able to click on some things, but not others. If I turn the anti aliasing up to 3 and hit best, it seems like it does nothing and all the menu buttons are unclickable.
Check for update to ZBrush. Try then once you have 4R6 P2.
Thanks, I’ll check it out. 