Disable assembly load context on content-start client.

Robust.Client/Console/Commands/ListAssembliesCommand.cs

@@ -0,0 +1,32 @@
+using System.Linq;
+using System.Runtime.Loader;
+using System.Text;
+using JetBrains.Annotations;
+using Robust.Client.Interfaces.Console;
+
+namespace Robust.Client.Console.Commands
+{
+    [UsedImplicitly]
+    internal sealed class ListAssembliesCommand : IConsoleCommand
+    {
+        public string Command => "lsasm";
+        public string Description => "Lists loaded assemblies by load context.";
+        public string Help => Command;
+
+        public bool Execute(IDebugConsole console, string[] args)
+        {
+            var sb = new StringBuilder();
+            foreach (var context in AssemblyLoadContext.All)
+            {
+                sb.AppendFormat("{0}:\n", context.Name);
+                foreach (var assembly in context.Assemblies.OrderBy(a => a.FullName))
+                {
+                    sb.AppendFormat("  {0}\n", assembly.FullName);
+                }
+            }
+
+            console.AddLine(sb.ToString());
+            return false;
+        }
+    }
+}

Robust.Client/ContentStart.cs

@@ -7,7 +7,7 @@ namespace Robust.Client
 #if FULL_RELEASE
             throw new System.InvalidOperationException("ContentStart is not available on a full release.");
 #else
-            GameController.Start(args);
+            GameController.Start(args, true);
 #endif
         }
     }

Robust.Client/GameController.cs

@@ -71,6 +71,7 @@ namespace Robust.Client
 #pragma warning restore 649
 
         private CommandLineArgs _commandLineArgs;
+        private bool _disableAssemblyLoadContext;
 
         public bool LoadConfigAndUserData { get; set; } = true;
 
@@ -136,6 +137,10 @@ namespace Robust.Client
 
             _fontManager.Initialize();
 
+            // Disable load context usage on content start.
+            // This prevents Content.Client being loaded twice and things like csi blowing up because of it.
+            _modLoader.SetUseLoadContext(!_disableAssemblyLoadContext);
+
             //identical code for server in baseserver
             if (!_modLoader.TryLoadAssembly<GameShared>(_resourceManager, $"Content.Shared"))
             {

Robust.Client/GameController/GameController.Standalone.cs

@@ -23,7 +23,7 @@ namespace Robust.Client
             Start(args);
         }
 
-        public static void Start(string[] args)
+        public static void Start(string[] args, bool contentStart = false)
         {
             if (_hasStarted)
             {
@@ -34,11 +34,11 @@ namespace Robust.Client
 
             if (CommandLineArgs.TryParse(args, out var parsed))
             {
-                ParsedMain(parsed);
+                ParsedMain(parsed, contentStart);
             }
         }
 
-        private static void ParsedMain(CommandLineArgs args)
+        private static void ParsedMain(CommandLineArgs args, bool contentStart)
         {
             IoCManager.InitThread();
 
@@ -48,6 +48,7 @@ namespace Robust.Client
 
             var gc = (GameController) IoCManager.Resolve<IGameController>();
             gc.SetCommandLineArgs(args);
+            gc._disableAssemblyLoadContext = contentStart;
             if (!gc.Startup())
             {
                 Logger.Fatal("Failed to start game controller!");

Robust.Shared/ContentPack/IModLoader.cs

@@ -44,5 +44,7 @@ namespace Robust.Shared.ContentPack
         ///     Sets the testing callbacks that will be passed to <see cref="GameShared.SetTestingCallbacks"/>.
         /// </summary>
         void SetModuleBaseCallbacks(ModuleTestingCallbacks testingCallbacks);
+
+        void SetUseLoadContext(bool useLoadContext);
     }
 }

Robust.Shared/ContentPack/ModLoader.cs

@@ -78,6 +78,8 @@ namespace Robust.Shared.ContentPack
 
         private static int _modLoaderId;
 
+        private bool _useLoadContext;
+
         public ModLoader()
         {
             var id = Interlocked.Increment(ref _modLoaderId);
@@ -88,6 +90,11 @@ namespace Robust.Shared.ContentPack
             _loadContext.Resolving += ResolvingAssembly;
         }
 
+        public void SetUseLoadContext(bool useLoadContext)
+        {
+            _useLoadContext = useLoadContext;
+        }
+
         public virtual void LoadGameAssembly<T>(Stream assembly, Stream symbols = null)
             where T : GameShared
         {
@@ -101,7 +108,15 @@ namespace Robust.Shared.ContentPack
 
             assembly.Position = 0;
 
-            var gameAssembly = _loadContext.LoadFromStream(assembly, symbols);
+            Assembly gameAssembly;
+            if (_useLoadContext)
+            {
+                gameAssembly = _loadContext.LoadFromStream(assembly, symbols);
+            }
+            else
+            {
+                gameAssembly = Assembly.Load(assembly.CopyToArray(), symbols.CopyToArray());
+            }
 
             InitMod<T>(gameAssembly);
         }
@@ -118,7 +133,16 @@ namespace Robust.Shared.ContentPack
             if (!AssemblyTypeChecker.CheckAssembly(diskPath))
                 return;
 
-            InitMod<T>(_loadContext.LoadFromAssemblyPath(diskPath));
+            Assembly assembly;
+            if (_useLoadContext)
+            {
+                assembly = _loadContext.LoadFromAssemblyPath(diskPath);
+            }
+            else
+            {
+                assembly = Assembly.LoadFrom(diskPath);
+            }
+            InitMod<T>(assembly);
         }
 
         protected void InitMod<T>(Assembly assembly) where T : GameShared