Plugins: Prevent app from starting without plugins

Il2CppInspector.CLI/Program.cs

@@ -169,6 +169,15 @@ namespace Il2CppInspector.CLI
             Console.WriteLine(asmInfo.LegalCopyright);
             Console.WriteLine("");
 
+            // Safe plugin manager load
+            try {
+                PluginManager.EnsureInit();
+            }
+            catch (Exception ex) when (ex is InvalidOperationException || ex is DirectoryNotFoundException) {
+                Console.Error.WriteLine(ex.Message);
+                Environment.Exit(1);
+            }
+
             // Check plugin options are valid
             if (!PluginOptions.ParsePluginOptions(options.PluginOptions, PluginOptions.GetPluginOptionTypes()))
                 return 1;

Il2CppInspector.Common/Plugins/Internal/PluginManager.cs

@@ -176,9 +176,13 @@ namespace Il2CppInspector
 
             AsInstance.ManagedPlugins.Clear();
 
-            // Don't do anything if there's no plugins folder
-            if (!Directory.Exists(pluginFolder))
-                return;
+            // Don't allow the user to start the application if there's no plugins folder
+            if (!Directory.Exists(pluginFolder)) {
+                throw new DirectoryNotFoundException(
+                    "Plugins folder not found. Please ensure you have installed the latest set of plugins before starting. "
+                  + "The plugins folder should be placed in the same directory as Il2CppInspector. "
+                  + "Use get-plugins.ps1 or get-plugins.sh to update your plugins. For more information, see the Il2CppInspector README.md file.");
+            }
 
             // Get every DLL
             // NOTE: Every plugin should be in its own folder together with its dependencies
@@ -317,6 +321,7 @@ namespace Il2CppInspector
             var eventInfo = new PluginOptionsChangedEventInfo();
 
             foreach (var plugin in EnabledPlugins)
+                if (plugin.Options != null)
                     foreach (var option in plugin.Options)
                         try {
                             option.Value = option.Value;

Il2CppInspector.GUI/App.xaml.cs

@@ -131,7 +131,7 @@ namespace Il2CppInspectorGUI
             // Load plugins if they aren't already
             try {
                 PluginManager.EnsureInit();
-            } catch (InvalidOperationException ex) {
+            } catch (Exception ex) when (ex is InvalidOperationException || ex is DirectoryNotFoundException) {
                 MessageBox.Show(ex.Message, "Fatal error loading plugins");
                 Environment.Exit(1);
             }