SOM 10.20 on VMware ESXi 6.5 won't start after installation


I've installed SOM 10.20 on a Windows Server 2012 R2 VM in a VMware ESXi 6.5 environment. After installation the ovstatus reports all processes running but the Web UI won't start.  The ERROR is the following: 

HTTP Status 404 - /som

type Status report

message /som

description The requested resource (/som) is not available.

Error report


Can someone suggest me how to solve it?

Previuosly I installed SOM v10.00 in the same enviroment having the same error.