This error was generated by Mod_Security. code example

Example: python requests.get pdf An appropriate representation of the requested resource could not be found

headers = {'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36'}
r = requests.get(url=urlLogin, params=params, headers=headers)