Open Browser Keyword of Selenium2Library (robotframework) is giving: is not a supported browser.

Hi,
I'm new in robotframework and I had wrote a keyword that should simply open a url in firfox:

Globals:
${fireFox_browser}    firefox
${ff_profile}           C:\\Users\\admin\\AppData\\Roaming\\Mozilla\\Firefox\\Profiles\\oz942dui.default

Open Browser  ${hola_url}  ${fireFox_browser} ff_profile_dir=${ff_profile}            
  Set Browser Implicit Wait 10 seconds
  Delete All Cookies
  Maximize Browser Window
  Input Text       css=.form-control.search.auto.tt-input ${url}  #input.form-control.search.auto.tt-input  
  Click Element    css=path.svg-icon-shackle

But when running it am getting:
| FAIL |
ValueError: firefox ff_profile_dir=C:\Python27\Lib\site-packages\Selenium2Library\resources\firefoxprofile is not a supported

Please advise what am missing!

Thanks.