how do I debug Internal_CallUpdateFunctions errors caused Unity upgrading a project 2018.3?

I opened a 2018.2 project in 2018.3 and accepted the auto upgrade request from the editor. Now every second the editor produces this error 30+ times

TargetParameterCountException: Number of parameters specified does not match the expected number.
System.Reflection.MonoMethod.ConvertValues (System.Reflection.Binder binder, System.Object[] args, System.Reflection.ParameterInfo[] pinfo, System.Globalization.CultureInfo culture, System.Reflection.BindingFlags invokeAttr) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Delegate.DynamicInvokeImpl (System.Object[] args) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Delegate.DynamicInvoke (System.Object[] args) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
Substance.Game.NativeFunctions.cppInitSubstance (System.String applicationDataPath) (at <1c8d849402bd45fbbc7729a858adad22>:0)
Substance.Game.NativeCallbacks.InitSubstance () (at <1c8d849402bd45fbbc7729a858adad22>:0)
Substance.Game.SubstanceMain.Initialize () (at <73d3aeb248aa4455be059d8925fa2f66>:0)
Substance.Game.SubstanceMain..cctor () (at <73d3aeb248aa4455be059d8925fa2f66>:0)
Rethrow as TypeInitializationException: The type initializer for 'Substance.Game.SubstanceMain' threw an exception.
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at /Users/builduser/buildslave/unity/build/Editor/Mono/EditorApplication.cs:200​

Any suggestions on how to track down the cause of this error? I can see it is happening in the Editor at line 200 and is related to substances and a call having the wrong number of parameters. How do I find out which substance or material is causing the problem?

Edit: Substances are not supported in 2018 according to the Substance Asset. I had not realised this and had had no problems with the plugin being in the project but not used, until this upgrade. Removing the plugin and all various Substance files under the Plugin directory solved the problem.

 

This issue came up during Unity 2018.3 beta a few times. It's caused by the Substance plugin in your project, which is not compatible with Unity 2018.3.

https://forum.unity.com/threads/unity-2018-3-is-now-available.593230/#post-4000249