Hello,
I have set up the Paypal Express Checkout module and entered the API Credentials.
But when I tried to test Paypal Express Checkout, it shows this message:

"This transaction is invalid. Please return to the recipient's website to complete your transaction using their regular checkout flow."

My Store URL is http://www.starruby.in/store/

I tried searching the forum for the solution to this problem, but couldnt find any relevant solution.

I also asked my hosting company about CURL and they replied saying that Curl is enabled on the server and they gave me this url for more details:
http://starruby.in/phpinfo.php

Please tell me what I am doing wrong?

Regards,
Harshil