Might be nothing but I get a

BodyDef Mech_Gekko has BodyPartRecord of MechanicalThorax whose children have more or equal coverage than 100% (111.00%)
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Warning (string)
Verse.BodyDef/<ConfigErrors>d__14:MoveNext ()
Verse.DefDatabase`1<Verse.BodyDef>:ErrorCheckAllDefs ()
System.Reflection.MonoMethod:Invoke (object,System.Reflection.BindingFlags,System.Reflection.Binder,object[],System.Globalization.CultureInfo)
System.Reflection.MethodBase:Invoke (object,object[])
Verse.GenGeneric:InvokeStaticMethodOnGenericType (System.Type,System.Type,string)
Verse.PlayDataLoader/<>c:<DoPlayLoad>b__4_1 (System.Type)
System.Threading.Tasks.Parallel/<>c__DisplayClass31_0`2<System.Type, object>:<ForEachWorker>b__0 (int)
System.Threading.Tasks.Parallel/<>c__DisplayClass17_0`1<object>:<ForWorker>b__1 ()
System.Threading.Tasks.Task:InnerInvoke ()
System.Threading.Tasks.Task:InnerInvokeWithArg (System.Threading.Tasks.Task)
System.Threading.Tasks.Task/<>c__DisplayClass178_0:<ExecuteSelfReplicating>b__0 (object)
System.Threading.Tasks.Task:InnerInvoke ()
System.Threading.Tasks.Task:Execute ()
System.Threading.Tasks.Task:ExecutionContextCallback (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.Tasks.Task:ExecuteWithThreadLocal (System.Threading.Tasks.Task&)
System.Threading.Tasks.Task:ExecuteEntry (bool)
System.Threading.Tasks.Task:System.Threading.IThreadPoolWorkItem.ExecuteWorkItem ()
System.Threading.ThreadPoolWorkQueue:Dispatch ()

hugs log

https://gist.github.com/4388fd64b9e1ab2c48fe919443944542