sir, please check firewall, in you use any antivirus please uninstall it and then check. if your problem solve reinstall antivirus and make sure antivirus not block ERA server application or ports.
also check using firefox 59
if problem not solve please rename c:\ERA to ERA_old and install ERA server again. if open ERA activation screen. do not activate and rename new ERA folder and again rename old ERA_old to ERA. and then check it.
please mark best answer if your problem solved.