diff --git a/TLSharp.Core/Network/MtProtoSender.cs b/TLSharp.Core/Network/MtProtoSender.cs
index d298b84..581b4db 100644
--- a/TLSharp.Core/Network/MtProtoSender.cs
+++ b/TLSharp.Core/Network/MtProtoSender.cs
@@ -267,6 +267,12 @@ namespace TLSharp.Core.Network
 					Debug.WriteLine($"Should wait {seconds} sec.");
 					Thread.Sleep(1000*seconds);
 				}
+				else if (errorMessage.StartsWith("PHONE_MIGRATE_"))
+				{
+					var resultString = Regex.Match(errorMessage, @"\d+").Value;
+					var dcIdx = int.Parse(resultString);
+					throw new InvalidOperationException($"Your phone number registered to {dcIdx} dc. Please update settings. See https://github.com/sochix/TLSharp#i-get-an-error-migrate_x for details.");
+				}
 				else
 				{
 					throw new InvalidOperationException(errorMessage);
@@ -332,7 +338,7 @@ namespace TLSharp.Core.Network
 					throw new InvalidOperationException("invalid container");
 
 			}
-			throw new NotImplementedException();
+			throw new NotImplementedException("This should never happens");
 			/*
 			logger.debug("bad_msg_notification: msgid {0}, seq {1}, errorcode {2}", requestId, requestSequence,
 						 errorCode);
@@ -397,7 +403,7 @@ namespace TLSharp.Core.Network
 
 			messageReader.BaseStream.Position -= 12;
 
-			throw new NotImplementedException();
+			throw new NotImplementedException("Handle future server salts function isn't implemented.");
 			/*
 			if (!runningRequests.ContainsKey(requestId))
 			{
diff --git a/TLSharp.Core/TelegramClient.cs b/TLSharp.Core/TelegramClient.cs
index 131ff12..859494b 100644
--- a/TLSharp.Core/TelegramClient.cs
+++ b/TLSharp.Core/TelegramClient.cs
@@ -14,12 +14,18 @@ namespace TLSharp.Core
 		private MtProtoSender _sender;
 		private AuthKey _key;
 		private readonly TcpTransport _transport;
-		private string _apiHash = "_your_hash";
-		private int _apiId = 0;
+		private string _apiHash = "a2514f96431a228e4b9ee473f6c51945";
+		private int _apiId = 19474;
 		private Session _session;
 
 		public TelegramClient(ISessionStore store, string sessionUserId)
 		{
+			if (_apiId == 0)
+				throw new InvalidOperationException("Your API_ID is invalid. Do a configuration first https://github.com/sochix/TLSharp#quick-configuration");
+
+			if (string.IsNullOrEmpty(_apiHash))
+				throw new InvalidOperationException("Your API_ID is invalid. Do a configuration first https://github.com/sochix/TLSharp#quick-configuration");
+
 			_transport = new TcpTransport();
 			_session = Session.TryLoadOrCreateNew(store, sessionUserId);
 		}
diff --git a/TLSharp.Tests/NotificatioClientTests.cs b/TLSharp.Tests/NotificatioClientTests.cs
index bdc08fa..800ba47 100644
--- a/TLSharp.Tests/NotificatioClientTests.cs
+++ b/TLSharp.Tests/NotificatioClientTests.cs
@@ -21,15 +21,30 @@ namespace TLSharp.Tests
 		{
 			// Setup your phone numbers in app.config
 			NumberToAuthenticate = ConfigurationManager.AppSettings["numberToAuthenticate"];
+			if (string.IsNullOrEmpty(NumberToAuthenticate))
+				throw new InvalidOperationException("NumberToAuthenticate is null");
+
 			RegisteredNumber = ConfigurationManager.AppSettings["registeredNumber"];
+			if (string.IsNullOrEmpty(RegisteredNumber))
+				throw new InvalidOperationException("RegisteredNumber is null");
+
 			UnregisteredNumber = ConfigurationManager.AppSettings["unregisteredNumber"];
-        }
+			if (string.IsNullOrEmpty(UnregisteredNumber))
+				throw new InvalidOperationException("UnregisteredNumber is null");
+
+			if (NumberToAuthenticate == UnregisteredNumber)
+				throw new InvalidOperationException("NumberToAuthenticate eqauls UnregisteredNumber but shouldn't!");
+
+			if (RegisteredNumber == UnregisteredNumber)
+				throw new InvalidOperationException("RegisteredNumber eqauls UnregisteredNumber but shouldn't!");
+		}
 
 		[TestMethod]
 		public async Task AuthUser()
 		{
 			var store = new FileSessionStore();
 			var client = new TelegramClient(store, "session");
+
 			await client.Connect();
 
 			var hash = await client.SendCodeRequest(NumberToAuthenticate);
@@ -70,6 +85,7 @@ namespace TLSharp.Tests
 
 			var store = new FileSessionStore();
 			var client = new Core.TelegramClient(store, "session");
+			
 			await client.Connect();
 
 			Assert.IsTrue(client.IsUserAuthorized());