Your issue is simple to resolve – new Macs have a firewall setting that blocks all applications unless you change the settings.
Here are the steps to fix it:
Select System Preferences.
Select Security when the System Preferences window appears on your screen.
Click on the Firewall tab.
Select the Stop button to disable your firewall. “Firewall Off” will now be displayed above the button.
If you want to stop here, the firewall is off and you will have open access to internet on all applications.
If you’d rather give permission for specific apps, like Revizzit, continue these instructions:
Configure advanced firewall options if you want to customize your firewall without completely disabling it.
Click on the Advanced button under the Firewall tab.
Place a check mark next to “Automatically allow signed software to receive incoming connections” if you want to give applications with valid certificates full access to your network at all times. This will eliminate any prompts you receive from these applications requesting permission or authorization.
Press the “plus” button to add or remove specific applications to or from the firewall. To add Revizzit:
Find Revizzit in your Applications folder and select it.
Click the “OK” button to save and apply your settings.
Now Revizzit can talk to the internet and bring you much joy :-)