Upgrade to SEP v12.1.6_MP1a failing

I'm attempting to upgrade an installation of 12.1.1 RU1 MP1 to  v12.1.6_MP1a and keep hitting a wall at this point:

I'm not very familiar with this product and am trying to upgrade a client's installation to facilitate support of Win 2012 server and Windows 8 clients which the previous version did not offer. 

SEP/SEPM is installed on a Windows 2003 SP2 box. I'm hoping this is a common issue with a known solution but I was unable to find anything. Any input appreciated.