As joomla developers ask, my robot.txt is in the root folder:

# If the Joomla site is installed within a folder
# eg www.example.com/joomla/ then the robots.txt file
# MUST be moved to the site root
# eg www.example.com/robots.txt
# AND the joomla folder name MUST be prefixed to all of the
# paths.
# eg the Disallow rule for the /administrator/ folder MUST
# be changed to read
# Disallow: /joomla/administrator/


But JSitemaps doesnt look there and think i dont have a robot.txt:

Inactive robots.txt detected

Is a bug? how can i solve it?