A red error I am getting is:
Exception loading def from file GeneDefs_Cosmetic.xml: System.ArgumentException: Could not find type named VanillaGenesExpanded.GeneExtension from node <li Class="VanillaGenesExpanded.GeneExtension"><customBloodThingDef>ST_Filth_Blood_Green</customBloodThingDef><customBloodIcon>Medical/Greenbleeding</customBloodIcon><customWoundsFromFleshtype>ST_WoundsGreen</customWoundsFromFleshtype><customBloodSmearThingDef>ST_Filth_BloodSmear_Green</customBloodSmearThingDef></li>
Parameter name: node
[Ref D1E5BBFB]
at Verse.DirectXmlToObjectNew.ResolveTypeForNode (System.Type defaultType, System.Xml.XmlNode node) [0x0005a] in <cb53cd4422904947932d33f561ad8d15>:0
(wrapper dynamic-method) Verse.DirectXmlToObjectNew+DummyTypeToHoldDynamicMethods.ParseAndSetListField_Verse_DefModExtension(object,System.Reflection.FieldInfo,System.Xml.XmlNode,System.Type)
(wrapper dynamic-method) Verse.DirectXmlToObjectNew+DummyTypeToHoldDynamicMethods.ParseAndReturnDef_Verse_Def(int,int,System.Xml.XmlNode,System.Type)
at Verse.DirectXmlToObjectNew.DefFromNodeNew (System.Xml.XmlNode node, Verse.LoadableXmlAsset loadingAsset) [0x00132] in <cb53cd4422904947932d33f561ad8d15>:0
- TRANSPILER net.pardeike.rimworld.lib.harmony: IEnumerable`1 VisualExceptions.ExceptionsAndActivatorHandler:Transpiler(IEnumerable`1 instructions, MethodBase original)
- PREFIX Dubwise.DubsBadHygiene: Boolean DubsBadHygiene.DubsBadHygieneMod:Prefix(XmlNode node, LoadableXmlAsset loadingAsset, Def& __result)

Possible Matches:
[Source: Starei's Florian Xenotype]
[File: D:\Steam\steamapps\workshop\content\294100\3310020641\1.5\Defs\GeneDefs\GeneDefs_Cosmetic.xml]

[Prepatcher, 0Harmony.dll] MonoMod.Utils.DynamicMethodDefinition.UnityEngine.StackTraceUtility.ExtractStackTrace_Patch1()
[Prepatcher, 0Harmony.dll] MonoMod.Utils.DynamicMethodDefinition.Verse.Log.Error_Patch5(System.String)
[Prepatcher, 0Harmony.dll] MonoMod.Utils.DynamicMethodDefinition.Verse.DirectXmlToObjectNew.DefFromNodeNew_Patch1(System.Xml.XmlNode, Verse.LoadableXmlAsset)
[Prepatcher, 0Harmony.dll] MonoMod.Utils.DynamicMethodDefinition.Verse.LoadedModManager.ParseAndProcessXML_Patch2(System.Xml.XmlDocument, System.Collections.Generic.Dictionary`2[System.Xml.XmlNode,Verse.LoadableXmlAsset], System.Boolean)
[Core, Assembly-CSharp.dll] Verse.LoadedModManager.LoadAllActiveMods(System.Boolean hotReload)
[Core, Assembly-CSharp.dll] Verse.PlayDataLoader.DoPlayLoad()
[Core, Assembly-CSharp.dll] Verse.PlayDataLoader.LoadAllPlayData(System.Boolean recovering)
[Core, Assembly-CSharp.dll] Verse.Root+<>c.<Start>b__10_1()
[Core, Assembly-CSharp.dll] Verse.LongEventHandler.RunEventFromAnotherThread(System.Action action)
[Core, Assembly-CSharp.dll] Verse.LongEventHandler+<>c.<UpdateCurrentAsynchronousEvent>b__28_0()
[System, mscorlib.dll] System.Threading.ThreadHelper.ThreadStart_Context(System.Object state)
[System, mscorlib.dll] System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx)
[System, mscorlib.dll] System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx)
[System, mscorlib.dll] System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state)
[System, mscorlib.dll] System.Threading.ThreadHelper.ThreadStart()

Log: https://gist.github.com/HugsLibRecordKeeper/d03b2cd134b1dcc22dbc3f078b26624c

Seems harmless since it's just about the green blood as filth type but maybe it helps fix some minor error.