Getting this error 6 times in a row at launch:

XML Verse.ThingDef defines the same field twice: drawGUIOverlay.

Field contents: true.

Whole XML:

<ThingDef ParentName="ChunkRockBase"><category>Item</category><thingClass>ThingWithComps</thingClass><altitudeLayer>Item</altitudeLayer><fillPercent>0.50</fillPercent><statBases><MaxHitPoints>300</MaxHitPoints><Flammability>0</Flammability><Beauty>-4</Beauty><Cleanliness>-2</Cleanliness><BeautyOutdoors>0</BeautyOutdoors><Mass>25</Mass></statBases><selectable>true</selectable><pathCost>42</pathCost><pathCostIgnoreRepeat>true</pathCostIgnoreRepeat><randomizeRotationOnSpawn>true</randomizeRotationOnSpawn><designateHaulable>true</designateHaulable><stackLimit>5</stackLimit><drawGUIOverlay>true</drawGUIOverlay><tradeability>None</tradeability><drawGUIOverlay>true</drawGUIOverlay><comps><li Class="CompProperties_Forbiddable" /></comps><description>A chunk of rock. Can be cut into usable stone blocks.</description><graphicData><texPath>Things/Item/Chunk/ChunkStone</texPath><graphicClass>ScatteredStones.Graphic_RandomSpread</graphicClass><flipExtraRotation>80</flipExtraRotation><color>(132,135,132)</color></graphicData><thingCategories><li>StoneChunks</li></thingCategories><defName>ChunkMarble</defName><label>marble chunk</label><soundDrop>ChunkRock_Drop</soundDrop><butcherProducts><BlocksMarble>20</BlocksMarble></butcherProducts><stuffProps><categories><li>Chunky</li></categories><statOffsets><WorkToBuild>140</WorkToBuild></statOffsets><color>(132,135,132)</color><soundImpactStuff>BulletImpact_Ground</soundImpactStuff><soundMeleeHitSharp>MeleeHit_Stone</soundMeleeHitSharp><soundMeleeHitBlunt>MeleeHit_Stone</soundMeleeHitBlunt><stuffAdjective>marble</stuffAdjective><statFactors><Beauty>1.35</Beauty><MarketValue>0.45</MarketValue><MaxHitPoints>1.2</MaxHitPoints><WorkToBuild>5.5</WorkToBuild><WorkToMake>1.15</WorkToMake></statFactors></stuffProps><resourceReadoutPriority>Middle</resourceReadoutPriority><modExtensions><li Class="ScatteredStones.RandomDraw"><minSize>0.82</minSize><maxSize>1.28</maxSize><offsetRange>0.27</offsetRange></li></modExtensions></ThingDef>
UnityEngine.StackTraceUtility:ExtractStackTrace ()
(wrapper dynamic-method) Verse.Log:Verse.Log.Error_Patch4 (string)
Verse.DirectXmlToObject:ObjectFromXml<Verse.ThingDef> (System.Xml.XmlNode,bool)
Verse.DirectXmlToObject:ObjectFromXmlReflection<Verse.ThingDef> (System.Xml.XmlNode,bool)
(wrapper dynamic-method) Verse.DirectXmlLoader:Verse.DirectXmlLoader.DefFromNode_Patch2 (System.Xml.XmlNode,Verse.LoadableXmlAsset)
(wrapper dynamic-method) Verse.LoadedModManager:Verse.LoadedModManager.ParseAndProcessXML_Patch2 (System.Xml.XmlDocument,System.Collections.Generic.Dictionary`2<System.Xml.XmlNode, Verse.LoadableXmlAsset>)
Verse.LoadedModManager:LoadAllActiveMods ()
Verse.PlayDataLoader:DoPlayLoad ()
Verse.PlayDataLoader:LoadAllPlayData (bool)
Verse.Root/<>c:<Start>b__6_1 ()
Verse.LongEventHandler:RunEventFromAnotherThread (System.Action)
Verse.LongEventHandler/<>c:<UpdateCurrentAsynchronousEvent>b__27_0 ()
System.Threading.ThreadHelper:ThreadStart_Context (object)
System.Threading.ExecutionContext:RunInternal (System.Threading.ExecutionContext,System.Threading.ContextCallback,object,bool)
System.Threading.ExecutionContext:Run (System.Threading.ExecutionContext,System.Threading.ContextCallback,object,bool)
System.Threading.ExecutionContext:Run (System.Threading.ExecutionContext,System.Threading.ContextCallback,object)
System.Threading.ThreadHelper:ThreadStart ()