SCCM 2012 R2 - Deploying a Management Point to Windows 2008 R2 server - HTTP test request failed, status code 500

Problem:

After remotely deploying a mangement point from your 2012 R2 primary server, the management point appears to install ok (i.e. the mpcontrol.log file appears in the %installlocaiton%\SMS\Logs folder). However, when you open the mpcontrol.log file, you notice that large portions of it are a vivd shade of red:

The key lines here are:

Call to HttpSendRequestSync failed for port 80 with status code 500, text:Internal Server Error

HTTP test request failed, status code 500, 'Internal Server Error'

Also, there may be some mention of a failure to connect to the SQL Server, e.g.

Failed to get connection to the configured SQL Database

Failed to connect to the configured SQL database.

Other Symptoms

navigating to http://servername/sms_mp/.sms_aut?MPList returns a blank page with a HTTP 500 error

Fixes to Try:

1] Assuming the MP and the SQL DB are in different parts of the network, ensure the firewall is allowing connections from the MP to the SQL DB (on TCP 1433 is the default). If the MP cannot talk to the SQL DB then this will cause all of the above errors to occur. 

2]  If you are only seeing the "Call to HttpSendRequestSync failed for port 80/443 with status code 500, text: Internal Server Error" message then you will need ASP.NET v4 with IIS (this doesn't need to be done in 2012 since this is enabled by default). Open an elevated command prompt and then enter the following:

cd /d %windir%\Microsoft.Net\Framework64\v4*
aspnet_regiis –i –enable

In a similar vein, you may also need to enable the 64-bit mode because IIS is configured to run in 32-bit mode, the ASP.NET installation does not create the ASP.NET registry keys in the 64-bit registry. To resolve this issue, type the following command in an elevated command prompt:

cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 0

Other very worthwhile links to check out:

http://scexblog.blogspot.co.uk/2013/12/call-to-httpsendrequestsync-failed-for.html
http://anoopcnair.com/2014/07/07/sccm-mp-internal-server-error-iss-call-httpsendrequestsync-failed-port-80-status-code-500/
http://systemcenterblog.hardac.co.uk/2013/04/note-to-self-configmgr-2012-sp1.html