Recently I have run into an issue in a customer PoC and encountered a weird issue. Everything looks fine except I cannot login UCSM. The UCSM code I am running is 2.1.3a, and I have got the error message:
"Login Error: java.io.IOException: Server returned HTTP response code: 400 for URL: http://ucsm_ip:443/nuova"
Eventually I've found out the JRE 7u45 update breaks this, after lowering the version it works fine now.