diff --git a/TLSharp.Core/Network/MtProtoSender.cs b/TLSharp.Core/Network/MtProtoSender.cs
index 107408a..d75584f 100644
--- a/TLSharp.Core/Network/MtProtoSender.cs
+++ b/TLSharp.Core/Network/MtProtoSender.cs
@@ -101,11 +101,26 @@ namespace TLSharp.Core.Network
             ulong remoteMessageId;
             int remoteSequence;
 
+            /*
+            if (body.Length<8)
+            {
+                List<byte> lb = new List<byte>();
+                foreach (var vb in body)
+                    lb.Add(vb);
+                for (int i = lb.Count; i < (8+16); i++)
+                    lb.Add(0);
+
+                body = lb.ToArray();
+            }
+            */
+
             using (var inputStream = new MemoryStream(body))
             using (var inputReader = new BinaryReader(inputStream))
             {
-                if (inputReader.BaseStream.Length < 8)
-                    throw new InvalidOperationException($"Can't decode packet");
+                if (inputReader.BaseStream.Length < 8)
+                {               
+                    throw new InvalidOperationException($"Can't decode packet");
+                }
 
                 ulong remoteAuthKeyId = inputReader.ReadUInt64(); // TODO: check auth key id
                 byte[] msgKey = inputReader.ReadBytes(16); // TODO: check msg_key correctness
@@ -342,7 +357,7 @@ namespace TLSharp.Core.Network
                 }
                 catch (ZlibException ex)
                 {
-
+                    Console.WriteLine(ex.Message);
                 }
             }
             else
@@ -512,6 +527,7 @@ namespace TLSharp.Core.Network
                 {
                     //	logger.error("failed to process message in contailer: {0}", e);
                     messageReader.BaseStream.Position = beginPosition + innerLength;
+                    Console.WriteLine(e.Message);
                 }
             }
 
diff --git a/TLSharp.Core/TelegramClient.cs b/TLSharp.Core/TelegramClient.cs
index 247daf8..2d1c71c 100644
--- a/TLSharp.Core/TelegramClient.cs
+++ b/TLSharp.Core/TelegramClient.cs
@@ -83,14 +83,23 @@ namespace TLSharp.Core
             if (dcOptions == null || !dcOptions.Any())
                 throw new InvalidOperationException($"Can't reconnect. Establish initial connection first.");
 
+            TLDcOption dc = null;
+            foreach (var d2 in dcOptions)
+            {
+                if (d2.Id == dcId && d2.Ipv6 == false)
+                {
+                    dc = d2;
+                    break;
+                }
+            }
+
             TLExportedAuthorization exported = null;
             if (_session.TLUser != null)
             {
                 TLRequestExportAuthorization exportAuthorization = new TLRequestExportAuthorization() { DcId = dcId };
-                exported = await SendRequestAsync<TLExportedAuthorization>(exportAuthorization,times);
+                exported = await SendRequestAsync<TLExportedAuthorization>(exportAuthorization, times);
             }
 
-            var dc = dcOptions.First(d => d.Id == dcId);
 
             _transport = new TcpTransport(dc.IpAddress, dc.Port, _handler);
             _session.ServerAddress = dc.IpAddress;
@@ -124,7 +133,7 @@ namespace TLSharp.Core
                 }
                 catch(DataCenterMigrationException e)
                 {
-                    if (times <= 1)
+                    if (times <= 150)
                     {
                         await ReconnectToDcAsync(e.DC, times + 1);
                         // prepare the request for another try
diff --git a/TLSharp.Core/Utils/Helpers.cs b/TLSharp.Core/Utils/Helpers.cs
index cff71ec..9cda1db 100644
--- a/TLSharp.Core/Utils/Helpers.cs
+++ b/TLSharp.Core/Utils/Helpers.cs
@@ -34,20 +34,20 @@ namespace TLSharp.Core.Utils
 
             Array.Copy(msgKey, 0, buffer, 0, 16);            // buffer[0:16] = msgKey
             Array.Copy(sharedKey, x, buffer, 16, 32);     // buffer[16:48] = authKey[x:x+32]
-            byte[] sha1a = sha1(buffer);                     // sha1a = sha1(buffer)
+            byte[] sha1a = Sha1(buffer);                     // sha1a = sha1(buffer)
 
             Array.Copy(sharedKey, 32 + x, buffer, 0, 16);   // buffer[0:16] = authKey[x+32:x+48]
             Array.Copy(msgKey, 0, buffer, 16, 16);           // buffer[16:32] = msgKey
             Array.Copy(sharedKey, 48 + x, buffer, 32, 16);  // buffer[32:48] = authKey[x+48:x+64]
-            byte[] sha1b = sha1(buffer);                     // sha1b = sha1(buffer)
+            byte[] sha1b = Sha1(buffer);                     // sha1b = sha1(buffer)
 
             Array.Copy(sharedKey, 64 + x, buffer, 0, 32);   // buffer[0:32] = authKey[x+64:x+96]
             Array.Copy(msgKey, 0, buffer, 32, 16);           // buffer[32:48] = msgKey
-            byte[] sha1c = sha1(buffer);                     // sha1c = sha1(buffer)
+            byte[] sha1c = Sha1(buffer);                     // sha1c = sha1(buffer)
 
             Array.Copy(msgKey, 0, buffer, 0, 16);            // buffer[0:16] = msgKey
             Array.Copy(sharedKey, 96 + x, buffer, 16, 32);  // buffer[16:48] = authKey[x+96:x+128]
-            byte[] sha1d = sha1(buffer);                     // sha1d = sha1(buffer)
+            byte[] sha1d = Sha1(buffer);                     // sha1d = sha1(buffer)
 
             byte[] key = new byte[32];                       // key = sha1a[0:8] + sha1b[8:20] + sha1c[4:16]
             Array.Copy(sha1a, 0, key, 0, 8);
@@ -66,18 +66,18 @@ namespace TLSharp.Core.Utils
         public static byte[] CalcMsgKey(byte[] data)
         {
             byte[] msgKey = new byte[16];
-            Array.Copy(sha1(data), 4, msgKey, 0, 16);
+            Array.Copy(Sha1(data), 4, msgKey, 0, 16);
             return msgKey;
         }
 
         public static byte[] CalcMsgKey(byte[] data, int offset, int limit)
         {
             byte[] msgKey = new byte[16];
-            Array.Copy(sha1(data, offset, limit), 4, msgKey, 0, 16);
+            Array.Copy(Sha1(data, offset, limit), 4, msgKey, 0, 16);
             return msgKey;
         }
 
-        public static byte[] sha1(byte[] data)
+        public static byte[] Sha1(byte[] data)
         {
             using (SHA1 sha1 = new SHA1Managed())
             {
@@ -85,7 +85,7 @@ namespace TLSharp.Core.Utils
             }
         }
 
-        public static byte[] sha1(byte[] data, int offset, int limit)
+        public static byte[] Sha1(byte[] data, int offset, int limit)
         {
             using (SHA1 sha1 = new SHA1Managed())
             {