[Xrystal]

Well this seems to be the calling block, so perhaps somewhere along the lines the unit_id resolves to a unit that doesn't have a name for some reason or the unit_id nils out :

local function onQueueUpdate( who, elapsed )

	queue_timer = queue_timer - elapsed;
	
	if queue_timer <= 0 then -- process the update queue at the user selected frame rate
	
		queue_timer = nUI_Unit.frame_rate;

		for unit_id in pairs( UpdateQueue ) do
		
			if UpdateQueue[unit_id] then
			
				UpdateQueue[unit_id] = false;
				unit_info = NewUnitInfo[unit_id];
								
				if LabelCallbacks[unit_id] and #LabelCallbacks[unit_id] > 0 then
					nUI_Unit:notifyCallbacks( 
						nUI_L["unit label"], LabelCallbacks, LabelUnits, 
						unit_info, unit_id, nUI_Unit:updateLabelInfo( unit_id, unit_info ) 
					);
				end
			end
		end
	end	
end