RimWorld 1.4.3563 rev533
报错如下
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Message (string)
RimWorld.VersionControl:LogVersionNumber ()
Verse.Root:CheckGlobalInit ()
Verse.Root:Start ()
Verse.Root_Entry:Start ()

Root level exception in OnGUI(): System.ArgumentNullException: Value cannot be null.
Parameter name: key
at System.Collections.Generic.Dictionary`2[TKey,TValue].FindEntry (TKey key) [0x00008] in <eae584ce26bc40229c1b1aa476bfa589>:0
at System.Collections.Generic.Dictionary`2[TKey,TValue].TryGetValue (TKey key, TValue& value) [0x00000] in <eae584ce26bc40229c1b1aa476bfa589>:0
at Verse.GenCollection.TryGetValue[T,V] (System.Collections.Generic.IDictionary`2[TKey,TValue] dict, T key, V fallback) [0x00000] in <8c412d4a16f94d4cb337e846f2dee469>:0
at ShellaBackgrounds.BackgroundsUtility.GetBackgroundImagePath () [0x00016] in <2c626c4d219947d4b282c7ae38591025>:0
at ShellaBackgrounds.Patch_UI_BackgroundMain_DoOverlay.ShowBGImageWhenLoading () [0x0001e] in <2c626c4d219947d4b282c7ae38591025>:0
at (wrapper dynamic-method) RimWorld.UI_BackgroundMain.RimWorld.UI_BackgroundMain.DoOverlay_Patch1(RimWorld.UI_BackgroundMain,UnityEngine.Rect)
at RimWorld.UI_BackgroundMain.BackgroundOnGUI () [0x000f7] in <8c412d4a16f94d4cb337e846f2dee469>:0
at Verse.LongEventHandler.LongEventsOnGUI () [0x001c5] in <8c412d4a16f94d4cb337e846f2dee469>:0
at Verse.Root.OnGUI () [0x00019] in <8c412d4a16f94d4cb337e846f2dee469>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
Verse.Root:OnGUI ()

发现问题了，没用我们的封面的时候在这会有个空引用，新订阅第一次也会这样，晚点传个版本修复