I have a UCS-C 220 Firmware versión: 1.5b, the server is new and clear.
So I tried to use a KVM to start the configuration, but the KVM never start.
I have a IE 11 and the last version of Java.
We've tried other versions of Java and Internet Explorer, plus disable the windows firewall and add exceptions of security to server´s ip in settings of java.
Are you seeing any downloads or pop-up's when you launch a KVM session? I find that this sometimes opens behind the open window and will timeout before I realize it. Depending on which browser you use, you may need to associate the downloaded .jnlp file with Java prior to getting prompt to accept this session.
I to have many issues with the KVM system of the UCS. The thing that will solved most of them for me is to flush the Java cache (temporary internet files ) in the control panel java applet. You may also remove all the install java apps and just run one version of it. Also make sure that in network setting your using Direct connection and not browser settings.