I upgraded my SLES 11 SP3 / OES11 SP2 server to SLES 11 SP4 / OES2015 SP1. The upgrade appeared to go OK but when it was configuring OES features at the end of the upgrade and specifically at the 'installing iManager Plugins' section, I got the error twice of "Unable to add the tree self-signed certificate to the root certificate store." I clicked 'OK' on the dialog (the only choice) both times and the upgrade continued. After the upgrade was finished and the server rebooted I tried logging into iManager. I got the login screen OK and filled in the correct credentials then clicked 'Login'. The browser screen went white and I could see in the address bar that it was trying to go to "https://x.y.z.33/nps/servlet/imanauthentication" but nothing happened. The screen stayed white.

I assume the two are related. I did a google search but there were only a couple hits and they were all from 2009 and 2010 and didn't appear to apply.

How do I fix the error I got about the self-signed cert and is that likely to fix the iManager issue?