"Protocol error in TDS stream" and "Client unable to establish connection due to prelogin failure" while connecting to SQL Server with Python

Question

Enviornment

At Server Side -

• OS: Windows NT 6.3
• DB: Microsoft SQL Server Standard 2014

At Client Side -

• Python: 3.7.3
• pyodbc: 4.0.27
• pymysql: 0.9.3
• OS: Windows 10
• driver: SQL Server Native Client 11.0 / ODBC Driver 13 for SQL Server

Issue

I am trying two different codes, which I know is correct, because they are running in a different system without any issue. The code is as follows:

Code 1:

import pymysql.cursors
conn = pymysql.connect(host='SomeRemoteServer',
                       user='UserIDForRemoteServer',
                       password='PassForRemoteServer',
                       db='DBNAME',
                       port=1433)
cursor = conn.cursor()

Error 1:

---------------------------------------------------------------------------
ConnectionResetError                      Traceback (most recent call last)
c:\users\jains\appdata\local\programs\python\python37\lib\site-packages\pymysql\connections.py in _read_bytes(self, num_bytes)
    690             try:
--> 691                 data = self._rfile.read(num_bytes)
    692                 break

c:\users\jains\appdata\local\programs\python\python37\lib\socket.py in readinto(self, b)
    588             try:
--> 589                 return self._sock.recv_into(b)
    590             except timeout:

ConnectionResetError: [WinError 10054] An existing connection was forcibly closed by the remote host

During handling of the above exception, another exception occurred:

OperationalError                          Traceback (most recent call last)
<ipython-input-3-396d851bab6d> in <module>
      4                        password='PassForRemoteServer',
      5                        db='DBNAME',
----> 6                        port=1433)
      7 cursor = conn.cursor()

c:\users\jains\appdata\local\programs\python\python37\lib\site-packages\pymysql\__init__.py in Connect(*args, **kwargs)
     92     """
     93     from .connections import Connection
---> 94     return Connection(*args, **kwargs)
     95 
     96 from . import connections as _orig_conn

c:\users\jains\appdata\local\programs\python\python37\lib\site-packages\pymysql\connections.py in __init__(self, host, user, password, database, port, unix_socket, charset, sql_mode, read_default_file, conv, use_unicode, client_flag, cursorclass, init_command, connect_timeout, ssl, read_default_group, compress, named_pipe, autocommit, db, passwd, local_infile, max_allowed_packet, defer_connect, auth_plugin_map, read_timeout, write_timeout, bind_address, binary_prefix, program_name, server_public_key)
    323             self._sock = None
    324         else:
--> 325             self.connect()
    326 
    327     def _create_ssl_ctx(self, sslp):

c:\users\jains\appdata\local\programs\python\python37\lib\site-packages\pymysql\connections.py in connect(self, sock)
    596             self._next_seq_id = 0
    597 
--> 598             self._get_server_information()
    599             self._request_authentication()
    600 

c:\users\jains\appdata\local\programs\python\python37\lib\site-packages\pymysql\connections.py in _get_server_information(self)
    973     def _get_server_information(self):
    974         i = 0
--> 975         packet = self._read_packet()
    976         data = packet.get_all_data()
    977 

c:\users\jains\appdata\local\programs\python\python37\lib\site-packages\pymysql\connections.py in _read_packet(self, packet_type)
    655         buff = b''
    656         while True:
--> 657             packet_header = self._read_bytes(4)
    658             #if DEBUG: dump_packet(packet_header)
    659 

c:\users\jains\appdata\local\programs\python\python37\lib\site-packages\pymysql\connections.py in _read_bytes(self, num_bytes)
    697                 raise err.OperationalError(
    698                     CR.CR_SERVER_LOST,
--> 699                     "Lost connection to MySQL server during query (%s)" % (e,))
    700             except BaseException:
    701                 # Don't convert unknown exception to MySQLError.

OperationalError: (2013, 'Lost connection to MySQL server during query ([WinError 10054] An existing connection was forcibly closed by the remote host)')

Code 2:

import pyodbc
conn = pyodbc.connect('DRIVER={SQL Server Native Client 11.0};SERVER=RemoteServerName;DATABASE=SomeDB;UID=UserNameToReadDB;PWD=PassForUser')

Error 2:

---------------------------------------------------------------------------
Error                                     Traceback (most recent call last)
<ipython-input-2-cc9028930f12> in <module>
      1 import pyodbc
----> 2 conn = pyodbc.connect('DRIVER={SQL Server Native Client 11.0};SERVER=RemoteServerName;DATABASE=SomeDB;UID=UserNameToReadDB;PWD=PassForUser')

Error: ('HY000', '[HY000] [Microsoft][SQL Server Native Client 11.0]Protocol error in TDS stream (0) (SQLDriverConnect); [HY000] [Microsoft][SQL Server Native Client 11.0]Client unable to establish connection due to prelogin failure (0)')

When I try to connect the same Server with same credentials with Microsoft SQL Server Management Studio 2017, it connects without any problem.

I have tried setting it up on ODBC Data Source Administrator, over there also it connected successfully. Initially same code was working on other laptop. Now I have changed the laptop, I am not sure what could be the issue...?

Please Suggest what I can do to access the Database.