After restarting Windows, FME Server Web UI not accessible

Symptom

Recently there have been reports after restarting a Windows Server system that FME Server WebUI becomes inaccessible.  Prior to the reboot of the server, FME Server was functioning correctly.  For this problem, this only affects FME Server when the Application Server is using port 80.  FME Server systems using port 8080 will not experience this particular issue.

When restarting the Windows Server, a 'new' SYSTEM process appears to start and occupies port 80, then when the FME Server Application Server service starts it can no longer bind with Port 80.  Errors can be seen in the tomcat logs related to the "bind" error. 

Confirm process using port 80
To confirm that a process is using port 80 run the following command in the Command Prompt:
netstat -nao | find ":80"
The results may indicate that a process is using port 80.

Here is an example showing the results of the command.  PID 9664 is using port 80, and in this case it is FME Server Application Server.  If this returns PID 4 then the system has encountered the issue reported here.



It may be possible to identify a new process or service that could be interfering with port 80.   In the 3 cases I have seen, 1 was solved by a service being identified and disabled, while the other two required the following workaround.
 

Workaround

If a service cannot be determined, a configuration change can be made to FME Server to change the service to port 80.
https://docs.safe.com/fme/html/FME_Server_Documentation/AdminGuide/Changing-Web-App-Server-Host-Name-Port.htm
The focus is on the port value and the instructions show how to change from it from 80 to 8080.  

Returning to Port 80?
Once you have the FME Server operating again on port 8080, involve your IT team to investigate the system to see if it is possible to determine the cause for the system process occupying port 80.  If resolved the workaround can be removed.  

Please leave comments if you have experienced this or have resolved this.