Try Winbox 4.
It should work, besides with the crappy Windows we (good?) ol’ time dinosaurs use (Windows XP, and SP2 while we are at it, in my case, and yes, I know) also with (hard core) Linux and (hipster) Mac, though being still in the works it has still some corners that needs be rounded.
Winbox 3 should be working through Wine.
The advanced users normally use terminal (via Winbox or ssh) anyway, so possible bugs in the rendering of Webfig are usually the last ones to be found/reported and later fixed by the good Mikrotik guys.
In order of reliability:
- terminal
- winbox (3)
- winbox (4)
- webfig
the last two could be viceversa.