I spent far too long trying to work out how to solve this problem and felt somewhat stupid afterwards!!
I am putting this up here as a reminder that, when deploying the ConfigMgr 2012 SP1 management point role on Windows 2008 R2 – to remember to register ASP.NET v4 with IIS, If you don’t do this, you will see something like this in your mpcontrol.log:
Call to HttpSendRequestSync failed for port 80/443 with status code 500, text: Internal Server Error
If you get this, and your site system is running Windows 2008 R2, then you might have forgotten to register ASP.NET version 4 with IIS. Prior to SP1 this was not an issue, as the management point web application ran using .Net version 3.5. This is actually a descendent of .Net version 2, which was the default ASP.NET option in this OS. When .Net v4 gets installed by the site server as part of the site system’s deployment, the ASP.NET version is not changed. With Server 2012, the default is .Net v4 so we don’t have to do this.
In order to fix this, we need to run the following command from an elevated command prompt (run as administrator):
cd /d %windir%\Microsoft.Net\Framework64\v4*
aspnet_regiis –i –enable
If you still have issues then try removing and re-adding the MP role..
P.S. My excuse for getting caught out by this is that I have been working with Server 2012 for so long that it slipped my mind