diff --git a/README.md b/README.md
index 23788ea537..e7ea29e58e 100644
--- a/README.md
+++ b/README.md
@@ -2,4 +2,4 @@ Wox   [![Build status](https://ci.appveyor.com/api/projects/status/bfktntbivg32e
 =========
 
 This is Wox Dev branch. We will develop new feature here and merge to master when we want to release a new version.  
-**Please send pull request to this branch if you wanto to contribute codes**
+**Please send pull request to this branch if you want to contribute codes**
diff --git a/Wox.Plugin.SystemPlugins/Calculator.cs b/Wox.Plugin.SystemPlugins/Calculator.cs
index c1f135482e..67602cc47b 100644
--- a/Wox.Plugin.SystemPlugins/Calculator.cs
+++ b/Wox.Plugin.SystemPlugins/Calculator.cs
@@ -49,8 +49,16 @@ namespace Wox.Plugin.SystemPlugins
                         SubTitle = "Copy this number to the clipboard", 
                         Action = (c) =>
                         {
-                            Clipboard.SetText(result.Result);
-                            return true;
+                            try
+                            {
+                                Clipboard.SetText(result.Result);
+                                return true;
+                            }
+                            catch (System.Runtime.InteropServices.ExternalException e)
+                            {
+                                MessageBox.Show("Copy failed, please try later");
+                                return false;
+                            }
                         }
                     } };
                 }
diff --git a/Wox.Plugin.SystemPlugins/WebSearch/WebSearchPlugin.cs b/Wox.Plugin.SystemPlugins/WebSearch/WebSearchPlugin.cs
index 97fe4e505e..67e1687055 100644
--- a/Wox.Plugin.SystemPlugins/WebSearch/WebSearchPlugin.cs
+++ b/Wox.Plugin.SystemPlugins/WebSearch/WebSearchPlugin.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
@@ -42,7 +42,7 @@ namespace Wox.Plugin.SystemPlugins
                         IcoPath = webSearch.IconPath,
                         Action = (c) =>
                         {
-                            Process.Start(webSearch.Url.Replace("{q}", keyword));
+                            Process.Start(webSearch.Url.Replace("{q}", Uri.EscapeDataString(keyword)));
                             return true;
                         }
                     }
@@ -66,7 +66,7 @@ namespace Wox.Plugin.SystemPlugins
                                     IcoPath = webSearch.IconPath,
                                     Action = (c) =>
                                     {
-                                        Process.Start(webSearch.Url.Replace("{q}", o));
+                                        Process.Start(webSearch.Url.Replace("{q}", Uri.EscapeDataString(o)));
                                         return true;
                                     }
                                 }).ToList());
diff --git a/Wox/Helper/ErrorReporting/ErrorReporting.cs b/Wox/Helper/ErrorReporting/ErrorReporting.cs
index 80063e1cdd..06e0eae107 100644
--- a/Wox/Helper/ErrorReporting/ErrorReporting.cs
+++ b/Wox/Helper/ErrorReporting/ErrorReporting.cs
@@ -28,26 +28,22 @@ namespace Wox.Helper.ErrorReporting
 
         public static void DispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
         {
-            if (System.Diagnostics.Debugger.IsAttached) return;
+            if (Debugger.IsAttached) return;
 
             e.Handled = true;
             string error = CreateExceptionReport("System.Windows.Application.DispatcherUnhandledException", e.Exception);
 
             Log.Error(error);
-            if (TryShowErrorMessageBox(error, e.Exception))
-            {
-                Environment.Exit(0);
-            }
+            TryShowErrorMessageBox(error, e.Exception);
         }
         public static void ThreadException(object sender, System.Threading.ThreadExceptionEventArgs e)
         {
-            if (System.Diagnostics.Debugger.IsAttached) return;
+            if (Debugger.IsAttached) return;
 
             string error = CreateExceptionReport("System.Windows.Forms.Application.ThreadException", e.Exception);
 
             Log.Fatal(error);
             TryShowErrorMessageBox(error, e.Exception);
-            Environment.Exit(0);
         }
 
         private static string CreateExceptionReport(string ev, object exceptionObject)
@@ -98,7 +94,7 @@ namespace Wox.Helper.ErrorReporting
             else
             {
                 sb.AppendLine(exceptionObject.GetType().FullName);
-                sb.AppendLine(new System.Diagnostics.StackTrace().ToString());
+                sb.AppendLine(new StackTrace().ToString());
                 sb.AppendLine("```");
                 sb.AppendLine();
             }