title: Python website log in: BIG-IP can not find session information in the request
body: <p>I have written the following code to enter into a website through python programming. But for some reason I am facing a error:</p>
  
  <p>**"Your session could not be established.</p>
  
  <p>BIG-IP can not find session information in the request. This can happen because your browser restarted after an add-on was installed. If this occurred, click the link below to continue. This can also happen because cookies are disabled in your browser. If so, enable cookies in your browser and start a new session."**</p>
  
  <p>My code(website, username and password hidden):</p>
  
  <pre><code>import sys
  import re
  import requests
  import csv
  from bs4 import BeautifulSoup
  from pprint import pprint
  
  login_url = "https://example.ex.com"
  
  with requests.Session() as session:
      proxy_url = "http://{0}:{1}@proxy.blah.blah.com:[portnumber]".format('proxy_uid', 'proxy_password')
      session.proxies = {'http': proxy_url, 'https': proxy_url}
      data = {
          'username': '_uname_',
          'password': '_Password_',
          'vhost': 'standard'
      }
      r = session.get(login_url)
      print r.cookies
      print r.headers
      r1 = session.post(login_url+'/my.policy', data=data)
      print r1.cookies
      print r1.headers
      print r1.reason
      with open("login.html", "w") as f:
          f.write(str(r1.content))
  </code></pre>
  
  <p>Any help is really appreciated! </p>