My program is in offline mode but I'm connected to the internet. How do I fix this?

This issue is commonly caused by a computer's firewall blocking Playground Sessions from accessing the internet. To fix this, visit the settings of your computer's anti-virus program and grant permission for Playground to access the internet.

Rarely, this can be caused by incorrect settings in Internet Explorer (Windows only).  If you cannot access the internet using Internet Explorer (even if it is not your default browser), fixing that can solve the issue.