[Crash] Game Crashes when starting the game in spectator mode

[steadyfield]

Red Alert 2 Mod at Version {DEV_VERSION}
on map e89ffc76c66bcce87c920eee3f424f847bb6dbce (Powder Keg by Westwood Studios).
Operating System: Windows (Microsoft Windows NT 6.2.9200.0)
Runtime Version: .NET CLR 4.0.30319.34209
Exception of type `System.NullReferenceException`
   at OpenRA.Mods.Common.Widgets.DropDownButtonWidget.Draw()
   at OpenRA.Widgets.Widget.DrawOuter() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Widgets\Widget.cs:Line 424
   at OpenRA.Widgets.Widget.DrawOuter() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Widgets\Widget.cs:Line 426
   at OpenRA.Widgets.Widget.DrawOuter() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Widgets\Widget.cs:Line 426
   at OpenRA.Widgets.Widget.DrawOuter() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Widgets\Widget.cs:Line 426
   at OpenRA.Widgets.Widget.DrawOuter() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Widgets\Widget.cs:Line 426
   at OpenRA.Widgets.Widget.DrawOuter() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Widgets\Widget.cs:Line 426
   at OpenRA.Widgets.Widget.DrawOuter() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Widgets\Widget.cs:Line 426
   at OpenRA.Widgets.Ui.Draw() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Widgets\Widget.cs:Line 77
   at OpenRA.Game.RenderTick() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Game.cs:Line 549
   at OpenRA.Game.Loop() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Game.cs:Line 666
   at OpenRA.Game.Run() in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Game.cs:Line 684
   at OpenRA.Program.Run(String[] args) in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Support\Program.cs:Line 117
   at OpenRA.Program.Main(String[] args) in d:\git\OpenRA-ra2-master-1031\OpenRA.Game\Support\Program.cs:Line 39