DYN-10745: Block non-built-in Autodesk Assistant / DynamoMCP instances

src/DynamoCore/Models/DynamoModel.cs

@@ -720,6 +720,11 @@ protected DynamoModel(IStartConfiguration config)
             NoNetworkMode = config.NoNetworkMode;
             HostAnalyticsInfo = config.HostAnalyticsInfo;
 
+            // DYN-10745: disabled in test mode since the suite routinely loads packages and
+            // extensions from directories outside Built-In Packages. Remove with DYN-10739.
+            LegacyAssistantExtensionGuard.Reset();
+            LegacyAssistantExtensionGuard.IsEnabled = !IsTestMode;
+
             DebugSettings = new DebugSettings();
             if (Logger == null)
             {

src/DynamoCore/Properties/Resources.en-US.resx

@@ -755,6 +755,9 @@ Parameter name: {0}</value>
   <data name="DuplicatedNewerPackage" xml:space="preserve">
     <value>A newer version of the package called {0} version {2} was found at {1} with version {3}. The newer version has been ignored.</value>
   </data>
+  <data name="LegacyAssistantPackageBlocked" xml:space="preserve">
+    <value>An outdated copy of {0} was found at {1}. Dynamo now includes {0} as a built-in package, so the older copy was not loaded. Delete the folder to complete your upgrade.</value>
+  </data>
   <data name="NoneLinterDescriptorName" xml:space="preserve">
     <value>None</value>
   </data>

src/DynamoCore/Properties/Resources.resx

@@ -757,6 +757,9 @@ Parameter name: {0}</value>
   <data name="DuplicatedNewerPackage" xml:space="preserve">
     <value>A newer version of the package called {0} version {2} was found at {1} with version {3}. The newer version has been ignored.</value>
   </data>
+  <data name="LegacyAssistantPackageBlocked" xml:space="preserve">
+    <value>An outdated copy of {0} was found at {1}. Dynamo now includes {0} as a built-in package, so the older copy was not loaded. Delete the folder to complete your upgrade.</value>
+  </data>
   <data name="Autocomplete" xml:space="preserve">
     <value>Autocomplete</value>
   </data>

src/DynamoCore/PublicAPI.Unshipped.txt

@@ -6,3 +6,4 @@ Dynamo.Models.DynamoModel.DefaultStartConfiguration.EnableUnTrustedLocationsNoti
 Dynamo.Models.DynamoModel.IStartConfiguration.EnableUnTrustedLocationsNotifications.get -> bool
 Dynamo.Models.DynamoModel.OpenFileCommand.OpenFileCommand(System.String filePath, System.Boolean forceManualExecutionMode, System.Boolean isTemplate, System.Boolean forceBlockRun) -> void
 Dynamo.Models.DynamoModel.InsertFileCommand.InsertFileCommand(System.String filePath, System.Boolean forceManualExecutionMode, System.Boolean forceBlockRun) -> void
+static Dynamo.Properties.Resources.LegacyAssistantPackageBlocked.get -> string

src/DynamoCore/Utilities/LegacyAssistantExtensionGuard.cs

@@ -0,0 +1,172 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using Dynamo.Core;
+
+namespace Dynamo.Utilities
+{
+    /// <summary>
+    /// A view extension blocked by <see cref="LegacyAssistantExtensionGuard"/>, recorded so a
+    /// single startup notification/dialog can be raised for it once the main window exists.
+    /// </summary>
+    internal readonly struct BlockedLegacyViewExtension
+    {
+        internal string DisplayName { get; }
+        internal string ManifestPath { get; }
+        internal string AssemblyPath { get; }
+
+        internal BlockedLegacyViewExtension(string displayName, string manifestPath, string assemblyPath)
+        {
+            DisplayName = displayName;
+            ManifestPath = manifestPath;
+            AssemblyPath = assemblyPath;
+        }
+    }
+
+    /// <summary>
+    /// DYN-10745 band-aid. Dynamo 4.2 ships Autodesk Assistant and DynamoMCP as built-in
+    /// packages for the first time. Older, pre-built-in copies of either extension are still
+    /// present on some machines (manual alpha installs, or files orphaned by a Revit
+    /// uninstall) and can silently displace the built-in copy or corrupt assembly resolution
+    /// order. This guard refuses to load either extension from any location outside Dynamo's
+    /// Built-In Packages directory.
+    /// Remove this entire type, and its call sites in PackageLoader.ScanPackageDirectory and
+    /// ViewExtensionLoader.Load(string), once DYN-10739 lands the permanent architectural fix.
+    /// </summary>
+    internal static class LegacyAssistantExtensionGuard
+    {
+        internal const string AutodeskAssistantTypeName = "Dynamo.AutodeskAssistant.AutodeskAssistantViewExtension";
+        internal const string McpViewExtensionTypeName = "Dynamo.MCP.McpViewExtension";
+
+        // Autodesk Assistant's package identity churned across DYN-10450
+        // (AutodeskAssistant -> DynamoAssistant -> back to AutodeskAssistant). Both names are
+        // treated as the same restricted package so a pre-rename install is still caught.
+        private static readonly Dictionary<string, string> restrictedPackageDisplayNames =
+            new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
+            {
+                { "AutodeskAssistant", "Autodesk Assistant" },
+                { "DynamoAssistant", "Autodesk Assistant" },
+                { "DynamoMCP", "DynamoMCP" }
+            };
+
+        private static readonly Dictionary<string, string> restrictedTypeDisplayNames =
+            new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
+            {
+                { AutodeskAssistantTypeName, "Autodesk Assistant" },
+                { McpViewExtensionTypeName, "DynamoMCP" }
+            };
+
+        // Package blocks record the package's ROOT DIRECTORY: a Dynamo package is a
+        // self-contained folder, so "delete this folder" is safe and correct advice.
+        private static readonly HashSet<string> blockedPackageDirectories =
+            new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+        // View-extension blocks record the individual manifest/assembly FILE paths, not a
+        // folder. A legacy install found this way (e.g. files orphaned directly under a
+        // Revit add-in folder by an uninstall) is not necessarily isolated in its own folder,
+        // so inferring "delete this folder" from the file's location could tell a user to
+        // delete something far broader than intended.
+        private static readonly List<BlockedLegacyViewExtension> blockedViewExtensions =
+            new List<BlockedLegacyViewExtension>();
+
+        /// <summary>
+        /// Whether the guard is active. Set from DynamoModel startup based on
+        /// !IsTestMode, so the existing test suite (which routinely loads packages and
+        /// extensions from directories outside Built-In Packages) is unaffected.
+        /// </summary>
+        internal static bool IsEnabled { get; set; }
+
+        /// <summary>
+        /// Looks up the friendly display name for a restricted package name. Returns false
+        /// for any package name that is not restricted.
+        /// </summary>
+        internal static bool TryGetRestrictedPackageDisplayName(string packageName, out string displayName)
+        {
+            displayName = null;
+            return packageName != null && restrictedPackageDisplayNames.TryGetValue(packageName, out displayName);
+        }
+
+        /// <summary>
+        /// Looks up the friendly display name for a restricted view extension TypeName.
+        /// Returns false for any TypeName that is not restricted.
+        /// </summary>
+        internal static bool TryGetRestrictedViewExtensionDisplayName(string typeName, out string displayName)
+        {
+            displayName = null;
+            return typeName != null && restrictedTypeDisplayNames.TryGetValue(typeName, out displayName);
+        }
+
+        /// <summary>
+        /// True if the given path is not located under Dynamo's Built-In Packages directory.
+        /// </summary>
+        internal static bool IsOutsideBuiltInPackages(string path)
+        {
+            if (string.IsNullOrEmpty(path)) return true;
+
+            var builtInDirectory = PathManager.BuiltinPackagesDirectory;
+            if (string.IsNullOrEmpty(builtInDirectory)) return true;
+
+            string fullPath;
+            string fullBuiltInDirectory;
+            try
+            {
+                fullPath = Path.GetFullPath(path);
+                fullBuiltInDirectory = Path.GetFullPath(builtInDirectory)
+                    .TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
+            }
+            catch (Exception ex) when (ex is ArgumentException || ex is NotSupportedException || ex is PathTooLongException)
+            {
+                return true;
+            }
+
+            // A plain StartsWith would let a sibling like "Built-In PackagesOld" pass as if it
+            // were under "Built-In Packages" -- require an exact match or a directory-separator
+            // boundary right after the prefix.
+            return !fullPath.Equals(fullBuiltInDirectory, StringComparison.OrdinalIgnoreCase) &&
+                !fullPath.StartsWith(fullBuiltInDirectory + Path.DirectorySeparatorChar, StringComparison.OrdinalIgnoreCase);
+        }
+
+        internal static void RecordBlockedPackage(string directory)
+        {
+            if (!string.IsNullOrEmpty(directory)) blockedPackageDirectories.Add(directory);
+        }
+
+        internal static void RecordBlockedViewExtension(string displayName, string manifestPath, string assemblyPath)
+        {
+            blockedViewExtensions.Add(new BlockedLegacyViewExtension(displayName, manifestPath, assemblyPath));
+        }
+
+        /// <summary>
+        /// View extensions blocked at that layer only. A block at the package layer already
+        /// raises its own startup notification via LibraryLoadFailedException, so those
+        /// packages are intentionally excluded here to avoid a duplicate notification.
+        /// </summary>
+        internal static IReadOnlyList<BlockedLegacyViewExtension> BlockedViewExtensions => blockedViewExtensions;
+
+        /// <summary>
+        /// The union of every path blocked by either gate (package folders and view-extension
+        /// files alike), for the consolidated startup dialog.
+        /// </summary>
+        internal static IReadOnlyCollection<string> AllBlockedPaths =>
+            blockedPackageDirectories
+                .Concat(blockedViewExtensions.SelectMany(b => new[] { b.ManifestPath, b.AssemblyPath }))
+                .Where(p => !string.IsNullOrEmpty(p))
+                .Distinct(StringComparer.OrdinalIgnoreCase)
+                .ToList();
+
+        internal static bool HasBlockedPaths =>
+            blockedPackageDirectories.Count > 0 || blockedViewExtensions.Count > 0;
+
+        /// <summary>
+        /// Clears all recorded state. Called once per DynamoModel construction so repeated
+        /// model instances in the same process (tests, multi-instance hosts) don't leak state
+        /// from a previous instance.
+        /// </summary>
+        internal static void Reset()
+        {
+            blockedPackageDirectories.Clear();
+            blockedViewExtensions.Clear();
+        }
+    }
+}

src/DynamoCoreWpf/Extensions/ViewExtensionLoader.cs

@@ -4,6 +4,7 @@
 using System.Reflection;
 using System.Xml;
 using Dynamo.Logging;
+using Dynamo.Utilities;
 using DynamoUtilities;
 
 namespace Dynamo.Wpf.Extensions
@@ -44,6 +45,8 @@ internal IViewExtension Load(ViewExtensionDefinition viewExtension)
 
         public IViewExtension Load(string extensionPath)
         {
+            extensionPath = Path.GetFullPath(extensionPath);
+
             var document = new XmlDocument();
             document.Load(extensionPath);
 
@@ -61,7 +64,7 @@ public IViewExtension Load(string extensionPath)
             {
                 if (item.Name == "AssemblyPath")
                 {
-                    path = Path.Combine(path, item.InnerText);
+                    path = Path.GetFullPath(Path.Combine(path, item.InnerText));
                     definition.AssemblyPath = path;
                 }
                 else if (item.Name == "TypeName")
@@ -85,6 +88,20 @@ public IViewExtension Load(string extensionPath)
                 }
             }
 
+            // DYN-10745: Dynamo 4.2 ships Autodesk Assistant and DynamoMCP as built-in
+            // extensions. Refuse to load either from any location outside Built-In Packages,
+            // before the assembly ever gets loaded. Remove this block once DYN-10739 lands
+            // the permanent fix.
+            if (LegacyAssistantExtensionGuard.IsEnabled &&
+                LegacyAssistantExtensionGuard.TryGetRestrictedViewExtensionDisplayName(definition.TypeName, out var restrictedDisplayName) &&
+                (LegacyAssistantExtensionGuard.IsOutsideBuiltInPackages(extensionPath) ||
+                 LegacyAssistantExtensionGuard.IsOutsideBuiltInPackages(definition.AssemblyPath)))
+            {
+                LegacyAssistantExtensionGuard.RecordBlockedViewExtension(restrictedDisplayName, extensionPath, definition.AssemblyPath);
+                Log($"Not loading outdated copy of {restrictedDisplayName}. Found at {extensionPath} and {definition.AssemblyPath}");
+                return null;
+            }
+
             var extension = Load(definition);
             return extension;
         }

src/DynamoCoreWpf/Properties/Resources.en-US.resx

@@ -1675,6 +1675,24 @@ Next assemblies were loaded several times:
   <data name="PackagePathAutoAddNotificationDetailedDescription" xml:space="preserve">
     <value>The import path "{0}" was added to "Node and Package Paths". If you want to update or remove this path, please open "Dynamo &gt; Preferences &gt;Package Manager &gt; Node and Package Paths..."</value>
   </data>
+  <data name="LegacyAssistantExtensionBlockedTitle" xml:space="preserve">
+    <value>Extension Not Loaded</value>
+  </data>
+  <data name="LegacyAssistantExtensionBlockedShortDescription" xml:space="preserve">
+    <value>An outdated copy of {0} was found and was not loaded.</value>
+  </data>
+  <data name="LegacyAssistantExtensionBlockedDetailedDescription" xml:space="preserve">
+    <value>Dynamo now includes {0} as a built-in extension. Delete the following to complete your upgrade, then restart Dynamo:
+{1}</value>
+  </data>
+  <data name="LegacyAssistantExtensionsModalTitle" xml:space="preserve">
+    <value>Outdated Autodesk Assistant / DynamoMCP Files Found</value>
+  </data>
+  <data name="LegacyAssistantExtensionsModalMessage" xml:space="preserve">
+    <value>Dynamo now includes Autodesk Assistant and DynamoMCP as built-in features. Older copies were found outside the built-in location and were not loaded. Delete the following, then restart Dynamo:
+
+{0}</value>
+  </data>
   <data name="PackageSearchStateNoResult" xml:space="preserve">
     <value>Search returned no results!</value>
   </data>

src/DynamoCoreWpf/Properties/Resources.resx

@@ -2357,6 +2357,24 @@ Do you want to install the latest Dynamo update?</value>
   <data name="PackagePathAutoAddNotificationDetailedDescription" xml:space="preserve">
     <value>The import path "{0}" was added to "Node and Package Paths". If you want to update or remove this path, please open "Dynamo &gt; Preferences &gt;Package Manager &gt; Node and Package Paths..."</value>
   </data>
+  <data name="LegacyAssistantExtensionBlockedTitle" xml:space="preserve">
+    <value>Extension Not Loaded</value>
+  </data>
+  <data name="LegacyAssistantExtensionBlockedShortDescription" xml:space="preserve">
+    <value>An outdated copy of {0} was found and was not loaded.</value>
+  </data>
+  <data name="LegacyAssistantExtensionBlockedDetailedDescription" xml:space="preserve">
+    <value>Dynamo now includes {0} as a built-in extension. Delete the following to complete your upgrade, then restart Dynamo:
+{1}</value>
+  </data>
+  <data name="LegacyAssistantExtensionsModalTitle" xml:space="preserve">
+    <value>Outdated Autodesk Assistant / DynamoMCP Files Found</value>
+  </data>
+  <data name="LegacyAssistantExtensionsModalMessage" xml:space="preserve">
+    <value>Dynamo now includes Autodesk Assistant and DynamoMCP as built-in features. Older copies were found outside the built-in location and were not loaded. Delete the following, then restart Dynamo:
+
+{0}</value>
+  </data>
   <data name="NodeContextMenuIsInput" xml:space="preserve">
     <value>Is Input</value>
   </data>