Add additional error messages on login failures

See #976

.github/ISSUE_TEMPLATE/bug_report.md

@@ -9,7 +9,7 @@ assignees: ''
 
 **Prerequisites**
  - [ ] I made sure I am running the latest [development build](https://ci.appveyor.com/project/ORelio/minecraft-console-client/build/artifacts)
- - [ ] I tried to [look for similar issues](https://github.com/ORelio/Minecraft-Console-Client/issues?q=is%3Aissue) before opening an new one
+ - [ ] I tried to [look for similar issues](https://github.com/ORelio/Minecraft-Console-Client/issues?q=is%3Aissue) before opening a new one
  - [ ] I have set `debugmessages=true` in config to diagnose my issue
  - [ ] I have redacted session tokens and passwords before attaching screenshots
 

.github/ISSUE_TEMPLATE/feature_request.md

@@ -10,7 +10,7 @@ assignees: ''
 **Prerequisites**
  - [ ] I have read and understood the [user manual](https://github.com/ORelio/Minecraft-Console-Client/tree/master/MinecraftClient/config)
  - [ ] I made sure I am running the latest [development build](https://ci.appveyor.com/project/ORelio/minecraft-console-client/build/artifacts)
- - [ ] I tried to [look for similar feature requests](https://github.com/ORelio/Minecraft-Console-Client/issues?q=is%3Aissue) before opening an new one
+ - [ ] I tried to [look for similar feature requests](https://github.com/ORelio/Minecraft-Console-Client/issues?q=is%3Aissue) before opening a new one
 
 **Feature description**
 A feature request should contain the following items:

.github/ISSUE_TEMPLATE/general-question.md

@@ -10,7 +10,7 @@ assignees: ''
 **Prerequisites**
  - [ ] I have read and understood the [user manual](https://github.com/ORelio/Minecraft-Console-Client/tree/master/MinecraftClient/config)
  - [ ] I made sure I am running the latest [development build](https://ci.appveyor.com/project/ORelio/minecraft-console-client/build/artifacts)
- - [ ] I tried to [look for similar questions](https://github.com/ORelio/Minecraft-Console-Client/issues?q=is%3Aissue) before creating an new one
+ - [ ] I tried to [look for similar questions](https://github.com/ORelio/Minecraft-Console-Client/issues?q=is%3Aissue) before creating a new one
 
 **Description of the Questions**
 Your question may contain the following items:

MinecraftClient/McTcpClient.cs

@@ -213,10 +213,15 @@ namespace MinecraftClient
                             timeoutdetector.Start();
                         }
                     }
+                    else
+                    {
+                        Console.WriteLine("Failed to login to this server.");
+                        retry = true;
+                    }
                 }
                 catch (Exception e)
                 {
-                    ConsoleIO.WriteLineFormatted("§8" + e.Message);
+                    ConsoleIO.WriteLineFormatted("§8" + e.GetType().Name + ": " + e.Message);
                     Console.WriteLine("Failed to join this server.");
                     retry = true;
                 }

MinecraftClient/Protocol/Handlers/Protocol16.cs

@@ -470,7 +470,11 @@ namespace MinecraftClient.Protocol.Handlers
 
                 return StartEncryption(uuid, username, sessionID, token, serverID, PublicServerkey);
             }
-            else return false;
+            else
+            {
+                ConsoleIO.WriteLineFormatted("§8Invalid response to Handshake packet");
+                return false;
+            }
         }
 
         private bool StartEncryption(string uuid, string username, string sessionID, byte[] token, string serverIDhash, byte[] serverKey)
@@ -486,6 +490,7 @@ namespace MinecraftClient.Protocol.Handlers
                 Console.WriteLine("Checking Session...");
                 if (!ProtocolHandler.SessionCheck(uuid, sessionID, CryptoHandler.getServerHash(serverIDhash, serverKey, secretKey)))
                 {
+                    handler.OnConnectionLost(ChatBot.DisconnectReason.LoginRejected, "Failed to check session.");
                     return false;
                 }
             }
@@ -520,7 +525,11 @@ namespace MinecraftClient.Protocol.Handlers
                 encrypted = true;
                 return true;
             }
-            else return false;
+            else
+            {
+                ConsoleIO.WriteLineFormatted("§8Invalid response to StartEncryption packet");
+                return false;
+            }
         }
 
         public bool Login()
@@ -555,9 +564,10 @@ namespace MinecraftClient.Protocol.Handlers
                             }
                         }
                     }
-                    catch
+                    catch (Exception e)
                     {
                         //Connection failed
+                        ConsoleIO.WriteLineFormatted("§8" + e.GetType().Name + ": " + e.Message);
                         return false;
                     }
                 }

MinecraftClient/Protocol/Handlers/Protocol18.cs

@@ -863,7 +863,10 @@ namespace MinecraftClient.Protocol.Handlers
                     login_phase = false;
 
                     if (!pForge.CompleteForgeHandshake())
+                    {
+                        ConsoleIO.WriteLineFormatted("§8Forge Login Handshake did not complete successfully");
                         return false;
+                    }
 
                     StartUpdating();
                     return true; //No need to check session or start encryption
@@ -920,7 +923,10 @@ namespace MinecraftClient.Protocol.Handlers
                     login_phase = false;
 
                     if (!pForge.CompleteForgeHandshake())
+                    {
+                        ConsoleIO.WriteLineFormatted("§8Forge StartEncryption Handshake did not complete successfully");
                         return false;
+                    }
 
                     StartUpdating();
                     return true;