[Bug] Error when launching HexEditor on pcsx2

[scowalt]

Steps to reproduce:

• Launch RTCV and pcsx2 (.\Development\Run.ps1 RTCV,pcsx2)
• Go to Advanced Memory Tools > Extra Tools Form > Open Hex Editor

Exception has been thrown by the target of an invocation.
   at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
   at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
   at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
   at System.Activator.CreateInstance(Type type, Boolean nonPublic)
   at System.Activator.CreateInstance(Type type)
   at RTCV.Common.S.GET[T]()
   at RTCV.Plugins.HexEditor.HexEditorConnector.<>c.<OnMessageReceived>b__1_0()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at RTCV.NetCore.SyncObjectSingleton.InvokeCorrectly(Control control, Delegate method, Object[] args)
   at RTCV.NetCore.SyncObjectSingleton.FormExecute(Action a)
   at RTCV.Plugins.HexEditor.HexEditorConnector.OnMessageReceived(Object sender, NetCoreEventArgs e)
   at RTCV.NetCore.LocalNetCoreRouter.Route(String endpointName, NetCoreEventArgs e)

Inner Exception: Exception has been thrown by the target of an invocation.
   at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
   at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
   at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
   at System.Activator.CreateInstance(Type type, Boolean nonPublic)
   at System.Activator.CreateInstance(Type type)
   at RTCV.Common.S.GET[T]()
   at RTCV.Plugins.HexEditor.HexEditorConnector.<>c.<OnMessageReceived>b__1_0()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at RTCV.NetCore.SyncObjectSingleton.InvokeCorrectly(Control control, Delegate method, Object[] args)
   at RTCV.NetCore.SyncObjectSingleton.FormExecute(Action a)
   at RTCV.Plugins.HexEditor.HexEditorConnector.OnMessageReceived(Object sender, NetCoreEventArgs e)
   at RTCV.NetCore.LocalNetCoreRouter.Route(String endpointName, NetCoreEventArgs e)

Based on the codepaths, this seems like something I likely regressed in #213. I'm not sure though