Re: Moodle 3.0 and Paypal Sandbox by Renaat Debleu - Tuesday, 20 December 2016, 3:15 AM Number of replies: 0 Possible causes:the PayPal servers cannot send data to your test installation (check your firewall and/or make your test site accessible to the world)timeouts in the communication between PayPal servers and your test server. Average of ratings: - Permalink Show parent Reply