Build fails due to "same field name is serialized multiple times error"

This is in Unity 5.6 for Nintendo 3DS. This error is blocking the Player build. I get the same error 3 times with no indication what class it is originating from. There are several plugin assemblies being used in this project.

This is the error:

The same field name is serialized multiple times in the class or its parent class. This is not supported: Base(MonoBehaviour) m_GameObject
UnityEditor.BuildPipeline:BuildPlayerInternalNoCheck(String[], String, String, BuildTargetGroup, BuildTarget, BuildOptions, Boolean)
UnityEditor.BuildPlayerWindow:BuildPlayerWithDefaultSettings(Boolean, BuildOptions, Boolean) (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:485)
UnityEditor.BuildPlayerWindow:BuildPlayerWithDefaultSettings(Boolean, BuildOptions) (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:339)
UnityEditor.BuildPlayerWindow:GUIBuildButtons(IBuildWindowExtension, Boolean, Boolean, Boolean, BuildPlatform) (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:1398)
UnityEditor.BuildPlayerWindow:ShowBuildTargetSettings() (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:1317)
UnityEditor.BuildPlayerWindow:OnGUI() (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:913)
System.Reflection.MonoMethod:InternalInvoke(Object, Object[], Exception&)
System.Reflection.MonoMethod:Invoke(Object, BindingFlags, Binder, Object[], CultureInfo) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
System.Reflection.MethodBase:Invoke(Object, Object[]) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115)
UnityEditor.HostView:Invoke(String, Object) (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:262)
UnityEditor.HostView:Invoke(String) (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:255)
UnityEditor.HostView:OnGUI() (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:84)

[C:\buildslave\unity\build\Runtime/Serialize/TransferFunctions/GenerateTypeTreeTransfer.cpp line 104]
(Filename: /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs Line: 222)

 

I'm getting this same error! I can't inherit from any class that inherits from monobehavior then because they all have this field "name"...

Apparently, the error is in the class MonoBehavior itself, as its stated in the second line of the error:
The same field name is serialized multiple times in the class or its parent class. This is not supported: Base(MonoBehaviour) m_GameObject

 

Bump. Same error 2019.1.3
I've got classes that use TMPro, and iTween, and sprite shader... all seem to trigger the bug.
Here is my error,
The same field name is serialized multiple times in the class or its parent class. This is not supported: Base(VisualTutorialTile3D) m_textMeshPro