PE2950 server 2008R2 How I fixed I used chrome to regain local access to the main page Then click on preferences on left side  go to general setting Solution 1 To use a new self signed Certificate change the SSL Encryption to Auto Negotiate Key Signing Algorithm (for Self Signed Certificate): choose SHA256 This will generate a new certificate if yours was expired or if you IE refused to open with old default and/or you saw schannel errors in event log when you tried to open the page click apply  your IE should now open but complain that your new cert is not trusted follow the prompts and add it to the trusted root certificate Authority for local machine  and you are done no need to back out patches or any thing else Solution 2 same location click on X.509 Certificate and import a new cert created from you AD  CA or public CA if you have bought one to use for a real web site and you are done Again not removing security patches! Enjoy 
I recently installed the latest batch (June 2016) of MS updates on our servers.  It went well except for two servers, a PE2950 and a PE2970, both running Server 2008R2.  These are our only two servers running Server 2008R2.  On both machines, after installing all the updates, I was unable to open OMSA.  The browser would display 'Internet Explorer cannot display the webpage'.  OMSA continued to work fine on the rest of our servers, most of which are running server 2008. I tried a different browser, but that didn't work.  OMSA was at 7.3, so I downloaded and installed 7.4.0 and the 7.4.0.2 update.  I found references to similar problems online, and some of the fixes included installing OMSA using the command prompt, or 'runas admin'.  I installed them every which way, but no matter how I installed it, I got the same result!  I didn't find any errors in the server's event logs.   So I started uninstalling updates until I found the one that broke it, and it was KB3161608.  Uninstalling that update fixed OMSA on both servers.   This updates is listed as optional, so I'm not sweating it for the time being.  I believe it's a certificate problem, and might be fixed by creating a new self-signed certificate for those servers, but this isn't really my area of expertise.  But I wanted to put this out there, in case it might help someone else.  
Dell OMSA - won't run after installation of KB3161608