Do you have the curl extension installed in your php installation?
Actually, I didn't get any idea about it.
So, how could I install that extension??
In Debian use sudo apt-get install php5-curl.
I tried this link: http://docs.moodle.org/25/en/admin/environment/php_extension/curl
and reinstall the Moodle again
but it's still the not working the add-on
Is their any other issue in this
Thanx
Firewall issue maybe? Is port 443 blocked?
Finally it solved
That was because of the blocked port in the university
Thanx Emma
Good deal - have fun with the plugins now!