Tip #1: Whitelist the Skillmill domain and app on your firewall. Here's how:
Whitelisting with the Windows Firewall
To manage the whitelist in the Windows Firewall, click Start, type firewall and click Windows Firewall. Click Allow a program or feature through Windows Firewall (or, if you’re using Windows 10, click Allow an app or feature through Windows Firewall).
On the next screen, click Change settings, then tick or untick the box next to an item to allow or block it. In this case, make sure the box to the left of Skillmill is ticked. On the right, tick both the Private and Public columns.
After clicking Ok to apply the settings, open the Skillmill app and launch a scenario. You should be able to play through the scenario.
If the error message appears again, follow the steps below to turn off the firewall.
Tip #2: Turn off firewall. A firewall may be set up on your computer which is preventing you from downloading updates.
How to check firewall status:
You can check your firewall status at any time within Windows. Click Start at the lower left corner of your screen. Click Control Panel in the column on the right side of the menu. Check the value next to Windows Firewall to determine if a firewall is turned on. If on, turn the firewall off.
Should you have any more questions or concerns, please feel free to reach out and email firstname.lastname@example.org