The article describes why can custo diag Server stop intermittently.
Tomcat by default runs on port number 8080, However there is high chance get a port conflict with others program. Sometime we just need to change the Tomcat port number.
(Source: https://www.mkyong.com/tomcat/how-to-change-tomcat-default-port/)
1) Locate server.xml in {Tomcat installation folder}\ conf \
2) Find following similar statement

or
3) About Tomcat’s server.xml file cites it’s runs on port 8080. Change the Connector port=”8080″ port to any other port number.
For example
Above statement instruct Tomcat server runs on port 8181.
4) Edit and save the server.xml file. Restart Tomcat. Done