From 5a829a3e98fd146f0a9725ae2aa57618e7f56282 Mon Sep 17 00:00:00 2001
From: Husam <numandina@gmail.com>
Date: Thu, 8 Jan 2026 08:38:55 +0300
Subject: [PATCH] Fix: Handle ReflectionTypeLoadException when loading
 assemblies

Assemblies with missing dependencies now get skipped instead of crashing
the MCP plugin build.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 .../root/Runtime/UnityMcpPlugin.Build.cs      | 31 ++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/Unity-MCP-Plugin/Assets/root/Runtime/UnityMcpPlugin.Build.cs b/Unity-MCP-Plugin/Assets/root/Runtime/UnityMcpPlugin.Build.cs
index b6ac4105d..a53cda2e4 100644
--- a/Unity-MCP-Plugin/Assets/root/Runtime/UnityMcpPlugin.Build.cs
+++ b/Unity-MCP-Plugin/Assets/root/Runtime/UnityMcpPlugin.Build.cs
@@ -10,7 +10,9 @@
 
 #nullable enable
 using System;
+using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 using com.IvanMurzak.McpPlugin;
 using com.IvanMurzak.ReflectorNet;
 using com.IvanMurzak.Unity.MCP.Utils;
@@ -95,12 +97,39 @@ protected virtual McpPlugin.Common.Version BuildVersion()
             return new UnityLoggerProvider();
         }
 
+        /// <summary>
+        /// Filters assemblies to only include those that can successfully load their types.
+        /// This prevents ReflectionTypeLoadException from assemblies with missing dependencies.
+        /// </summary>
+        protected virtual IEnumerable<Assembly> GetSafeAssemblies()
+        {
+            foreach (var assembly in AppDomain.CurrentDomain.GetAssemblies())
+            {
+                if (assembly.IsDynamic)
+                    continue;
+
+                try
+                {
+                    assembly.GetTypes();
+                    yield return assembly;
+                }
+                catch (ReflectionTypeLoadException)
+                {
+                    _logger.LogWarning("Skipping assembly with missing dependencies: {assembly}", assembly.GetName().Name);
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning("Skipping assembly {assembly}: {error}", assembly.GetName().Name, ex.Message);
+                }
+            }
+        }
+
         protected virtual IMcpPlugin BuildMcpPlugin(McpPlugin.Common.Version version, Reflector reflector, ILoggerProvider? loggerProvider = null)
         {
             _logger.LogTrace("{method} called.",
                 nameof(BuildMcpPlugin));
 
-            var assemblies = AppDomain.CurrentDomain.GetAssemblies();
+            var assemblies = GetSafeAssemblies().ToArray();
             var mcpPlugin = new McpPluginBuilder(version, loggerProvider)
                 .WithConfig(config =>
                 {