Okay, maybe not a nice fix, or even permanent, but the following stops the errors and the buttons are still usable from what I could see. Downside is that some of the extra nUI buttons that were linked to the micro buttons are no longer there.
File: nUI_MicroMenu.lua
Around Line: 205 - Comment this positioning block out. The moment these buttons are setpointed in nUI it triggers an error with the setpoint call.
Lua Code:
--[[
button:ClearAllPoints();
if i == 1 then
width = (btnWidth+0.6) * btn_scale;
button:SetPoint( "BOTTOMLEFT", frame, "BOTTOMLEFT", 3 * scale * nUI.hScale, 3 * scale * nUI.vScale )
else
button:SetPoint( "LEFT", last_button, "RIGHT", btn_gap, 0 );
width = width + (btnWidth+0.6) * btn_scale + btn_gap;
end
--]]
Notice the difference with the buttons.
Edit: Looking at Vrul's changes it looks like the setpoints are the cause.