Your computer may be connecting to the internet through a firewall, this is common if you are connecting from inside a school or inside a corporate office.
You or your network administrator need to allow ALL of the following domain names to be accessible. To quickly check you can click on each link to see if the (proper criteria) shows up.
- comp01.123d.circuits.io (you should see "Cannot GET /")
- assets.circuits.io (you should see a version of the 123D Circuits web site)
If you are still having problems please proceed to Step 4: Contact Support.