Multiple ingredients with an unfinished object

[theguruofreason]

I am attempting to make an item that requires 2 different resources to produce; leather and steel. I also want it to have an 'unfinished' stage. The recipe seems to work fine, except that when I inspect the unfinished object I get these errors:

(Filename:  Line: 398)

Exception doing inspect pane: System.ArgumentOutOfRangeException: Argument is out of range.

Parameter name: index

  at System.Collections.Generic.List`1[Verse.ThingCount].get_Item (Int32 index) [0x00000] in <filename unknown>:0

  at Verse.UnfinishedThing.get_LabelBase () [0x00000] in <filename unknown>:0

  at Verse.Thing.get_Label () [0x00000] in <filename unknown>:0

  at Verse.Thing.get_LabelCap () [0x00000] in <filename unknown>:0

  at RimWorld.InspectPaneUtility.AdjustedLabelFor (IEnumerable`1 selected, Rect rect) [0x00000] in <filename unknown>:0

  at RimWorld.InspectPane.InspectPaneOnGUI () [0x00000] in <filename unknown>:0

(Filename: C:/BuildAgent/work/d63dfc6385190b60/artifacts/StandalonePlayerGenerated/UnityEngineDebug.cpp Line: 49)

GUI Error: You are pushing more GUIClips than you are popping. Make sure they are balanced)

(Filename:  Line: 398)

Exception doing inspect pane: System.ArgumentOutOfRangeException: Argument is out of range.

Parameter name: index

  at System.Collections.Generic.List`1[Verse.ThingCount].get_Item (Int32 index) [0x00000] in <filename unknown>:0

  at Verse.UnfinishedThing.get_LabelBase () [0x00000] in <filename unknown>:0

  at Verse.Thing.get_Label () [0x00000] in <filename unknown>:0

  at Verse.Thing.get_LabelCap () [0x00000] in <filename unknown>:0

  at RimWorld.InspectPaneUtility.AdjustedLabelFor (IEnumerable`1 selected, Rect rect) [0x00000] in <filename unknown>:0

  at RimWorld.InspectPane.InspectPaneOnGUI () [0x00000] in <filename unknown>:0

(Filename: C:/BuildAgent/work/d63dfc6385190b60/artifacts/StandalonePlayerGenerated/UnityEngineDebug.cpp Line: 49)

Not having many examples to draw from, I'm unsure what is causing this problem. Also, when I mouse over the object all of the gui panes disappear. I can post the XML if needed. Please halp!