O Erro
Ao tentar acessar a interface web para configurar o endian o seguinte erro acontecia:
Service Unavailable The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later. Additionally, a 503 Service Unavailable error was encountered while trying to use an ErrorDocument to handle the request.
O Log
Consultando o Log do Endian aparece o seguinte evento:
Jul 26 13:16:09 efw httpd: [Mon Jul 26 13:16:08.877265 2021] [cgid:error] [pid 2403:tid 140290895582976] (2)No such file or directory: [client 192.168.20.44:36614] AH01257: unable to connect to cgi daemon after multiple tries: /home/httpd/html/errors/502error.cgi
Solução
Acessei o Endian via ssh e reiniciei o apache:
/etc/init.d/httpd restart