Could a firewall be blocking ATI or LockDown Browser? How to check and fix it

A firewall protects your computer by controlling what can connect to it and what it can connect to. Most of the time it stays out of the way, but a firewall — or the security software that manages it — can block ATI pages from loading or stop Respondus LockDown Browser from connecting during a remote exam. This article shows you how to tell if that’s what’s happening and what to do about it.

Signs a firewall may be blocking you

• atitesting.com pages won’t load, time out, or show a connection error while other websites work normally.
• LockDown Browser installs but can’t connect, or the Dry Run fails to start.
• The webcam or microphone check fails even though the camera and mic work in other apps.
• Everything works on your phone’s hotspot or at home, but not on your school, work, or public network.

Quick test: connect your computer to a different network (for example, your phone’s hotspot) and try again. If it works there, something on the original network or computer is blocking the connection. Also make sure you are not connected to a VPN — see How do I see if I am using a VPN?

On Windows 10 and 11

1. Click Start, type Windows Security, and press Enter.
2. Click Firewall & network protection.
3. Look at the top of the page. If it says the firewall is managed by another program (for example Norton, McAfee, or Bitdefender), that program controls your firewall — open it and check its firewall or “web protection” settings instead of Windows Security. Otherwise, continue.
4. Click Allow an app through firewall, then Change settings (you may need your administrator password).
5. Find LockDown Browser in the list and make sure the Private box is checked. If it isn’t listed, click Allow another app…, browse to it, and add it. Click OK.
6. Restart LockDown Browser and try the Dry Run again.

On a Mac

macOS 13 (Ventura) and later:

1. Click the Apple menu and choose System Settings.
2. Click Network in the sidebar, then Firewall.
3. If the firewall is on, click Options…. Make sure Block all incoming connections is off and that LockDown Browser is set to Allow incoming connections (add it with the + button if it isn’t listed).
4. Click OK, then restart LockDown Browser and try the Dry Run again.

macOS 12 (Monterey) and earlier: open System Preferences › Security & Privacy › Firewall, click the padlock to make changes, then Firewall Options… and follow step 3 above.

On an iPad

iPadOS does not have a firewall you can adjust. If ATI or LockDown Browser won’t connect on an iPad, the block is almost always on the network (school, work, or public Wi-Fi) or a VPN or content-filter profile. Try a different network, turn off any VPN under Settings › General › VPN & Device Management, and see Resolve remote proctored computer issues using Respondus.

On a school, work, or public network

If you are using a computer or network managed by a school or employer, the firewall is usually controlled by their IT department and you won’t be able to change it. Contact IT and ask them to allow access to atitesting.com and Respondus LockDown Browser — or, if that isn’t possible, take your exam on a personal computer using your home network or a phone hotspot.

Still blocked?

1. Temporarily turn off any third-party antivirus or security software, restart your computer, and run the Dry Run again. Turn the software back on after your exam.
2. Confirm your computer meets the system requirements and that LockDown Browser is up to date. Reinstalling it resolves many connection issues — see Resolve remote proctored computer issues using Respondus.
3. If you see Error 1020, that is a location block rather than a firewall — see What is an error 1020?