I'm trying to install version 6.2.1 using the Web Platform Installer method and it can't get past installing the SQL shared management objects.  There are two dependencies-- the 2012 Shared Management Objects and the 2008 R2 Management Objects.  When I try to let the installer install them, it errors out with a "Value cannot be null" message from the debugger.  If I use the supplied links to download and install each component separately, they seem to install OK but then the Web Platform Installer does not see both of them and tries to install one of  them again, resulting in the same error.  Whichever was the last one to install (2008 vs 2012) seems to interfere with the other.  So if I install the 2008 objects, the 2012 dependency shows up when installing DNN, then if I install the 2012 objects the 2008 objects show up as missing again on the DNN install.  It just goes back and forth like this and there is no way to get them both installed.