When launch LE5 Publisher and Player for the first time, Shall I grant access on Windows Security Alert window?

When you launch LE5 Publisher or Player for the first time, a Windows Security Alert window will popup as shown in the below image. You need to click on "Allow access" so the Publisher and Player can communicate without errors.

This alert window will disappear after a while, if you did not get a chance to click on "Allow access", you need to go to Windows firewall setting to grant the access.

To go to Windows firewall "Allowed apps" screen, type "allow an file through windows firewall" in Windows search box, see the below image, click on the search result "Allow an app through Windows Firewall"

On the "Allowed apps" screen, locate the "Node.js: Server-side JavaScript" entry from the "Allowed apps and features" list, see the below image. Make sure all three check boxes are checked. If not checked, click on "Change settings", check the boxes, then click on "OK"