OffScreen fails to load with BadImageFormatException when running in Godot 4.0

[emelrad12]

• What version of the product are you using?
  Version=112.2.70.0
  CefSharp.OffScreen.NETCore

• What architecture x86 or x64?
  x64

• What version of .Net?
  6.0
  But it is using actually Godot.NET.Sdk/4.0.2
  Which seems to be a fork of Microsoft.NET.Sdk

• On what operating system?
  Win11

• Are you using WinForms, WPF or OffScreen?
  OffScreen

• What steps will reproduce the problem?
  Make a new Godot c# project and import Cef sharp into it
  Try to load a new ChromiumWebBrowser()

• What is the expected output? What do you see instead?
  I get this exception
  ERROR: System.BadImageFormatException: Could not load file or assembly 'CefSharp.Core.Runtime, Version=112.2.70.0, Culture=neutral, PublicKeyToken=40c4b6fc221f4138'. An attempt was made to load a program with an incorrect format.
  File name: 'CefSharp.Core.Runtime, Version=112.2.70.0, Culture=neutral, PublicKeyToken=40c4b6fc221f4138' ---> System.BadImageFormatException: Could not load file or assembly ''. An attempt was made to load a program with an incorrect format.
  File name: ''
  at System.Runtime.Loader.AssemblyLoadContext.InternalLoad(ReadOnlySpan1 arrAssembly, ReadOnlySpan1 arrSymbols)
  at System.Runtime.Loader.AssemblyLoadContext.LoadFromStream(Stream assembly, Stream assemblySymbols)
  at GodotPlugins.PluginLoadContext.Load(AssemblyName assemblyName) in /root/godot/modules/mono/glue/GodotSharp/GodotPlugins/PluginLoadContext.cs:line 69
  at System.Runtime.Loader.AssemblyLoadContext.ResolveUsingLoad(AssemblyName assemblyName)
  at System.Runtime.Loader.AssemblyLoadContext.Resolve(IntPtr gchManagedAssemblyLoadContext, AssemblyName assemblyName)
  at CefSharp.Cef.get_IsInitialized()
  at CefSharp.OffScreen.ChromiumWebBrowser..ctor(String address, IBrowserSettings browserSettings, IRequestContext requestContext, Boolean automaticallyCreateBrowser, Action`1 onAfterBrowserCreated, Boolean useLegacyRenderHandler) in C:\projects\cefsharp\CefSharp.OffScreen\ChromiumWebBrowser.cs:line 213
  at WeirdGame.UI.CefMain.Init() in D:\Projects\WeirdGame\Src\UI\CefMain.cs:line 11
  at WeirdGame.GameMain._Ready() in D:\Projects\WeirdGame\GameMain.cs:line 28
  at Godot.Node.InvokeGodotClassMethod(godot_string_name& method, NativeVariantPtrArgs args, godot_variant& ret) in /root/godot/modules/mono/glue/GodotSharp/GodotSharp/Generated/GodotObjects/Node.cs:line 1801
  at WeirdGame.GameMain.InvokeGodotClassMethod(godot_string_name& method, NativeVariantPtrArgs args, godot_variant& ret) in D:\Projects\WeirdGame\Godot.SourceGenerators\Godot.SourceGenerators.ScriptMethodsGenerator\WeirdGame.GameMain_ScriptMethods.generated.cs:line 40
  at Godot.Bridge.CSharpInstanceBridge.Call(IntPtr godotObjectGCHandle, godot_string_name* method, godot_variant** args, Int32 argCount, godot_variant_call_error* refCallError, godot_variant* ret) in /root/godot/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/CSharpInstanceBridge.cs:line 24

• Does this problem also occur in the CEF Sample Application
  No, it is only related to using godot

Note that Godot switched to net 6.0(not using mono anymore) recently and is using a fork of the net sdk, so most likely CefSharp is having an issue with that.

[amaitland]

In future please use Discussions to ask support related questions.

• What architecture x86 or x64?
  x64

Did you set a RuntimeIdentifier?

• What steps will reproduce the problem?
  Make a new Godot c# project and import Cef sharp into it
  Try to load a new ChromiumWebBrowser()

I've never even heard of Godot. This is meaningless to me.

Our diagnostics for mixed-mode assembly loading need a bit of work since they throw a BadImageFormatException for basically every failure.

As per dotnet/runtime#31743 (comment) the .Net Runtime will throw a BadImageFormatException for any failure

• System.BadImageFormatException: Could not load file or assembly ''. An attempt was made to load a program with an incorrect format.

As above, for .Net 6.0 the exception means there was a failure, it doesn't tell us what failed. It could be anything. Best guess is it's failing to load some dependencies.

• /root/godot/modules/mono/glue/GodotSharp/GodotPlugins/PluginLoadContext.cs:line 69

If setting a RuntimeIdentifier doesn't resolve the problem then this is what I'd suggest you start debugging.

Note that Godot switched to net 6.0(not using mono anymore) recently and is using a fork of the net sdk, so most likely CefSharp is having an issue with that.

What makes this a CefSharp issue exactly? If Godot is using a custom SDK then for me this is a Gotdot issue.

[nmeyvis]

@emelrad12 did you get offscreen working with godot4? im running into this same issue.

[emelrad12]

No, there is a package for godot 4.0, search for gdcef, maybe that works.