GUI: Don't allow plugins to run without validating options at least once

Il2CppInspector.Common/Plugins/PluginManager.cs

@@ -50,6 +50,13 @@ namespace Il2CppInspector
         public string Operation { get; set; }
     }
 
+    // Event arguments for option handler
+    public class PluginOptionErrorEventArgs : PluginErrorEventArgs
+    {
+        // The option causing the problem
+        public IPluginOption Option { get; set; }
+    }
+
     // Event arguments for the status handler
     public class PluginStatusEventArgs : EventArgs
     {
@@ -247,6 +254,24 @@ namespace Il2CppInspector
             return eventInfo;
         }
 
+        // Validate all options for enabled plugins
+        public static PluginOptionsChangedEventInfo ValidateAllOptions() {
+            // Enforce this by causing each option's setter to run
+            var eventInfo = new PluginOptionsChangedEventInfo();
+
+            foreach (var plugin in EnabledPlugins)
+                foreach (var option in plugin.Options)
+                    try {
+                        option.Value = option.Value;
+                    }
+                    catch (Exception ex) {
+                        eventInfo.Error = new PluginOptionErrorEventArgs { Plugin = plugin, Exception = ex, Option = option, Operation = "options update" };
+                        ErrorHandler?.Invoke(AsInstance, eventInfo);
+                        break;
+                    }
+            return eventInfo;
+        }
+
         // Try to cast each enabled plugin to a specific interface type, and for those supporting the interface, execute the supplied delegate
         // Errors will be forwarded to the error handler
         internal static E Try<I, E>(Action<I, E> action) where E : PluginEventInfo, new()

Il2CppInspector.GUI/App.xaml.cs

@@ -70,7 +70,15 @@ namespace Il2CppInspectorGUI
 
         public List<AppModel> AppModels { get; } = new List<AppModel>();
 
-        public Exception LastException { get; private set; }
+        private Exception _lastException;
+        public Exception LastException {
+            get {
+                var ex = _lastException;
+                _lastException = null;
+                return ex;
+            }
+            private set => _lastException = value;
+        }
 
         // Event to indicate current work status
         public event EventHandler<string> OnStatusUpdate;
@@ -84,8 +92,11 @@ namespace Il2CppInspectorGUI
 
             // Set handlers for plugin manager
             PluginManager.ErrorHandler += (s, e) => {
-                if (e is PluginOptionsChangedEventInfo)
+                if (e is PluginOptionsChangedEventInfo oe)
-                    MessageBox.Show("Could not update plugin options. " + e.Error.Exception.Message, "Plugin error");
+                    if (oe.Error is PluginOptionErrorEventArgs oea)
+                        MessageBox.Show($"Plugin option '{oea.Option.Description}' for {e.Error.Plugin.Name} is invalid: {e.Error.Exception.Message}", "Plugin error");
+                    else
+                        MessageBox.Show($"One or more plugin options for {e.Error.Plugin.Name} are invalid: {e.Error.Exception.Message}", "Plugin error");
                 else
                     MessageBox.Show($"The plugin {e.Error.Plugin.Name} encountered an error while executing {e.Error.Operation}: {e.Error.Exception.Message}."
                                 + Environment.NewLine + Environment.NewLine + "Plugin has been disabled.", "Plugin error");
@@ -131,6 +142,10 @@ namespace Il2CppInspectorGUI
         public Task<bool> LoadMetadataAsync(MemoryStream metadataStream) =>
             Task.Run(() => {
                 try {
+                    // Don't start unless every enabled plugin's options are valid
+                    if (PluginManager.ValidateAllOptions().Error != null)
+                        return false;
+
                     metadata = Metadata.FromStream(metadataStream, StatusUpdate);
                     return true;
                 }

Il2CppInspector.GUI/MainWindow.xaml.cs

@@ -121,7 +121,8 @@ namespace Il2CppInspectorGUI
             else {
                 areaBusyIndicator.Visibility = Visibility.Hidden;
                 grdFirstPage.Visibility = Visibility.Visible;
-                MessageBox.Show(this, app.LastException.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
+                if (app.LastException is Exception e)
+                    MessageBox.Show(this, e.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
             }
         }
 
@@ -157,7 +158,8 @@ namespace Il2CppInspectorGUI
             else {
                 areaBusyIndicator.Visibility = Visibility.Hidden;
                 btnSelectBinaryFile.Visibility = Visibility.Visible;
-                MessageBox.Show(this, app.LastException.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
+                if (app.LastException is Exception e)
+                    MessageBox.Show(this, e.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
             }
         }
 
@@ -195,7 +197,8 @@ namespace Il2CppInspectorGUI
             else {
                 areaBusyIndicator.Visibility = Visibility.Hidden;
                 grdFirstPage.Visibility = Visibility.Visible;
-                MessageBox.Show(this, app.LastException.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
+                if (app.LastException is Exception e)
+                    MessageBox.Show(this, e.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
             }
         }