Hmmm, strange exception.
Is it possible that TimeSpan is not supported in net461 ?

[2022/09/30 11:29:37][INFO] // BeforeActualRun
[2022/09/30 11:29:37][INFO]
[2022/09/30 11:29:37][INFO] System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidOperationException: The type System.TimeSpan was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.
[2022/09/30 11:29:37][INFO] at System.Xml.Serialization.XmlSerializationWriter.WriteTypedPrimitive(String name, String ns, Object o, Boolean xsiType)
[2022/09/30 11:29:37][INFO] at System.Xml.Tests.Perf_XmlSerializationWriter.AddPrimitives()
[2022/09/30 11:29:37][INFO] at BenchmarkDotNet.Autogenerated.Runnable_734.WorkloadActionUnroll(Int64 invokeCount)
[2022/09/30 11:29:37][INFO] at BenchmarkDotNet.Engines.Engine.RunIteration(IterationData data)
[2022/09/30 11:29:37][INFO] at BenchmarkDotNet.Engines.EngineStage.RunIteration(IterationMode mode, IterationStage stage, Int32 index, Int64 invokeCount, Int32 unrollFactor)
[2022/09/30 11:29:37][INFO] at BenchmarkDotNet.Engines.EngineActualStage.RunSpecific(Int64 invokeCount, IterationMode iterationMode, Int32 iterationCount, Int32 unrollFactor)
[2022/09/30 11:29:37][INFO] at BenchmarkDotNet.Engines.EngineActualStage.Run(Int64 invokeCount, IterationMode iterationMode, Boolean runAuto, Int32 unrollFactor, Boolean forceSpecific)
[2022/09/30 11:29:37][INFO] at BenchmarkDotNet.Engines.Engine.Run()
[2022/09/30 11:29:37][INFO] at BenchmarkDotNet.Autogenerated.Runnable_734.Run(IHost host, String benchmarkName)

I receive some warning at the end :

// * Warnings *
MinIterationTime
Perf_XmlSerializationWriter.AddPrimitives: PowerPlanMode=00000000-0000-0000-0000-000000000000, Toolchain=CoreRun, InvocationCount=1, IterationTime=250.0000 ms, MaxIterationCount=20, MinIterationCount=15, UnrollFactor=1, WarmupCount=1 -> The minimum observed iteration time is 19.3454 ms which is very small. It's recommended to increase it to at least 100.0000 ms using more operations.

What should I change to solve it ?