EasyNPC on linux (MO2)

[Endryl42]

[Question/Issue] Running EasyNPC on Linux via Proton/Wine fails with NotImplementedException in ModernWpf

Hello,

I'm trying to run EasyNPC on Linux (Linux Mint) through Steam's Proton (and Wine), as part of a Skyrim SE modding setup with Mod Organizer 2. The application starts but crashes immediately with a specific exception related to the ModernWpf library.

I have followed the standard steps for running Windows tools on Linux for Skyrim modding:

Game & Tools: Skyrim SE (Steam), Mod Organizer 2 (via Portable instance), EasyNPC.

Environment: Configured the Proton prefix for Skyrim (App ID 489830) to use Windows 10 via winecfg.

Dependencies: Installed vcrun2022 and the .NET 5.0 Desktop Runtime (version 5.0.17) into the prefix.

MO2 Integration: The tool is added to MO2's executables. USVFS hooks are injected successfully (confirmed in logs).

The Problem / Error:
When executing EasyNPC.exe directly via Wine/Proton, it crashes. The terminal shows a long error, but the core issue appears to be a System.NotImplementedException when ModernWpf tries to call a specific Windows API.

The key error lines are:
text

System.NotImplementedException: The method or operation is not implemented.
at WinRT.EventSource1.Subscribe(TDelegate del) at Windows.UI.ViewManagement.UISettings.add_ColorValuesChanged(TypedEventHandler2 value)
at ModernWpf.ColorsHelper.ListenToSystemColorChanges()

This suggests the ModernWpf library relies on Windows.UI.ViewManagement.UISettings.add_ColorValuesChanged, which is not implemented in the current Wine/Proton build I'm using (Wine 9.0 from Ubuntu repos / Proton Experimental).

Full Context & Logs:
A more complete log from a recent run is here:
text
[leny@Leny-Mint:~/Games/mod-organizer-2-skyrimspecialedition/modorganizer2/Tools/EasyNPC-0.9.6$ grep -A 20 -B 5 "System.NotImplementedException" easynpc_error.log
012c:err:setupapi:create_dest_file failed to create L"C:\windows\system32\xpssvcs.dll" (error=80)
wine: configuration in L"/home/leny/.steam/steam/steamapps/compatdata/489830/pfx" has been updated.
---> System.TypeInitializationException: The type initializer for 'ModernWpf.ThemeManager' threw an exception.
---> System.TypeInitializationException: The type initializer for 'ModernWpf.ColorsHelper' threw an exception.
---> System.NotImplementedException: The method or operation is not implemented.
at System.Runtime.InteropServices.Marshal.ThrowExceptionForHR(Int32 errorCode)
at WinRT.ExceptionHelpers.GetExceptionForHR(Int32 hr, Boolean useGlobalErrorState, Boolean& restoredExceptionFromGlobalState)
at WinRT.ExceptionHelpers.g__Throw|20_0(Int32 hr)
at WinRT.ExceptionHelpers.ThrowExceptionForHR(Int32 hr)
at WinRT.EventSource1.Subscribe(TDelegate del) at Windows.UI.ViewManagement.UISettings.add_ColorValuesChanged(TypedEventHandler2 value)
at ModernWpf.ColorsHelper.ListenToSystemColorChanges()
at ModernWpf.ColorsHelper..ctor()
at ModernWpf.ColorsHelper..cctor()
--- End of inner exception stack trace ---
at ModernWpf.ThemeManager..cctor()
--- End of inner exception stack trace ---
at ModernWpf.ThemeManager.get_Current()
at ModernWpf.ThemeResources.EndInit()
at ModernWpf.ThemeResources.System.ComponentModel.ISupportInitialize.EndInit()
at MS.Internal.Xaml.Runtime.ClrObjectRuntime.InitializationGuard(XamlType xamlType, Object obj, Boolean begin)
--- End of inner exception stack trace ---
at System.Windows.Markup.XamlReader.RewrapException(Exception e, IXamlLineInfo lineInfo, Uri baseUri)
at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
at System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri)

0144:err:eventlog:ReportEventW L".NET Version: 5.0.17\n"
0144:err:eventlog:ReportEventW L"Description: The process was terminated due to an unhandled exception.\n"
0144:err:eventlog:ReportEventW L"Exception Info: System.Windows.Markup.XamlParseException: A inicializa\00e7\00e3o de 'ModernWpf.ThemeResources' iniciou uma exce\00e7\00e3o.\r\n"
0144:err:eventlog:ReportEventW L" ---> System.TypeInitializationException: The type initializer for 'ModernWpf.ThemeManager' threw an exception.\r\n"
0144:err:eventlog:ReportEventW L" ---> System.TypeInitializationException: The type initializer for 'ModernWpf.ColorsHelper' threw an exception.\r\n"
0144:err:eventlog:ReportEventW L" ---> System.NotImplementedException: The method or operation is not implemented.\r\n"
0144:err:eventlog:ReportEventW L" at System.Runtime.InteropServices.Marshal.ThrowExceptionForHR(Int32 errorCode)\r\n"
0144:err:eventlog:ReportEventW L" at WinRT.ExceptionHelpers.GetExceptionForHR(Int32 hr, Boolean useGlobalErrorState, Boolean& restoredExceptionFromGlobalState)\r\n"
0144:err:eventlog:ReportEventW L" at WinRT.ExceptionHelpers.g__Throw|20_0(Int32 hr)\r\n"
0144:err:eventlog:ReportEventW L" at WinRT.ExceptionHelpers.ThrowExceptionForHR(Int32 hr)\r\n"
0144:err:eventlog:ReportEventW L" at WinRT.EventSource1.Subscribe(TDelegate del)\r\n" 0144:err:eventlog:ReportEventW L" at Windows.UI.ViewManagement.UISettings.add_ColorValuesChanged(TypedEventHandler2 value)\r\n"
0144:err:eventlog:ReportEventW L" at ModernWpf.ColorsHelper.ListenToSystemColorChanges()\r\n"
0144:err:eventlog:ReportEventW L" at ModernWpf.ColorsHelper..ctor()\r\n"
0144:err:eventlog:ReportEventW L" at ModernWpf.ColorsHelper..cctor()\r\n"
0144:err:eventlog:ReportEventW L" --- End of inner exception stack trace ---\r\n"
0144:err:eventlog:ReportEventW L" at ModernWpf.ThemeManager..cctor()\r\n"
0144:err:eventlog:ReportEventW L" --- End of inner exception stack trace ---\r\n"
0144:err:eventlog:ReportEventW L" at ModernWpf.ThemeManager.get_Current()\r\n"
0144:err:eventlog:ReportEventW L" at ModernWpf.ThemeResources.EndInit()\r\n"
0144:err:eventlog:ReportEventW L" at ModernWpf.ThemeResources.System.ComponentModel.ISupportInitialize.EndInit()\r\n"
0144:err:eventlog:ReportEventW L" at MS.Internal.Xaml.Runtime.ClrObjectRuntime.InitializationGuard(XamlType xamlType, Object obj, Boolean begin)\r\n"
0144:err:eventlog:ReportEventW L" --- End of inner exception stack trace ---\r\n"
0144:err:eventlog:ReportEventW L" at System.Windows.Markup.XamlReader.RewrapException(Exception e, IXamlLineInfo lineInfo, Uri baseUri)\r\n"
0144:err:eventlog:ReportEventW L" at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)\r\n"
0144:err:eventlog:ReportEventW L" at System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri)\r\n"
grep: easynpc_error.log: arquivo binário coincide com o padrão
leny@Leny-Mint:~/Games/mod-organizer-2-skyrimspecialedition/modorganizer2/Tools/EasyNPC-0.9.6$ ]

My Questions:

Is there any known workaround, configuration, or specific version of Proton/Wine that can make EasyNPC's ModernWpf interface work on Linux?

Are there any plans to consider Linux/Proton compatibility, perhaps by using a different UI framework or providing a fallback mode for unsupported APIs?

This tool is fantastic for managing NPC appearance mods, and having it run on Linux would be a huge help for the growing Linux modding community. Thank you for your time and for creating EasyNPC.

System Info:

OS: Linux Mint 21.x (based on Ubuntu 22.04)

Wine/Proton: Wine 9.0 (system), Proton Experimental (Steam)

Game: The Elder Scrolls V: Skyrim Special Edition (Steam, App ID 489830)

Mod Manager: Mod Organizer 2 (Portable instance)

[monyarm]

Adding an override to have EasyNPC be run in Windows8.1 mode makes it work.
Unfortunately, when run through MO2, it tried to look for the ini in MO2 base folder, rather than the profile in question.

[prnvp23]

This tool is fantastic for managing NPC appearance mods, and having it run on Linux would be a huge help for the growing Linux modding community. Thank you for your time and for creating EasyNPC.

Seconded, I'm on Steam Deck and would love to be able to run this tool rather than mess around with SSEEdit without fully understanding it.