CheckSequenceSprites does not check Widgets

[Mailaender]

Exception of type `System.InvalidOperationException`: Unit `field` does not have a sequence named `icon`
  at OpenRA.Graphics.SequenceProvider.GetSequence (System.String unitName, System.String sequenceName) [0x0005d] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/SequenceProvider.cs:80 
  at OpenRA.Graphics.Animation.GetSequence (System.String sequenceName) [0x00000] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/Animation.cs:234 
  at OpenRA.Graphics.Animation.PlaySequence (System.String sequenceName) [0x00000] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/Animation.cs:115 
  at OpenRA.Graphics.Animation.PlayThen (System.String sequenceName, System.Action after) [0x00022] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/Animation.cs:149 
  at OpenRA.Graphics.Animation.Play (System.String sequenceName) [0x00000] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/Animation.cs:104 
  at OpenRA.Mods.Common.Widgets.ProductionPaletteWidget.RefreshIcons () [0x00193] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Mods.Common/Widgets/ProductionPaletteWidget.cs:408 
  at OpenRA.Mods.Common.Widgets.ProductionPaletteWidget.set_CurrentQueue (OpenRA.Mods.Common.Traits.ProductionQueue value) [0x00007] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Mods.Common/Widgets/ProductionPaletteWidget.cs:101

Exception of type `System.InvalidOperationException`: Unit `icon` does not have any sequences defined.
  at OpenRA.Graphics.SequenceProvider.GetSequence (System.String unitName, System.String sequenceName) [0x0005d] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/SequenceProvider.cs:80 
  at OpenRA.Graphics.Animation.GetSequence (System.String sequenceName) [0x00000] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/Animation.cs:234 
  at OpenRA.Graphics.Animation.PlaySequence (System.String sequenceName) [0x00000] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/Animation.cs:115 
  at OpenRA.Graphics.Animation.PlayThen (System.String sequenceName, System.Action after) [0x00022] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/Animation.cs:149 
  at OpenRA.Graphics.Animation.Play (System.String sequenceName) [0x00000] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Game/Graphics/Animation.cs:104 
  at OpenRA.Mods.Common.Widgets.SupportPowersWidget.RefreshIcons () [0x0011d] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Mods.Common/Widgets/SupportPowersWidget.cs:141 
  at OpenRA.Mods.Common.Widgets.SupportPowersWidget.Tick () [0x00000] in /home/matthias/Entwicklung/OpenHV/engine/OpenRA.Mods.Common/Widgets/SupportPowersWidget.cs:244

is not caught beforehand.