We have no idea of telling what it is this early. No trainer has worked for Windows 8 that we know of and would recommend using Windows 7 or earlier if you wish to use trainers. More than likely it's just Windows being incomplete as the current preview is targeted at developers, not consumers.
[Edited by Neo7, 2/22/2012 8:23:52 PM]
--------------------------------------------------------------------------- Your bitterness, I will dispel
How did you get authentication to work? All the old trainers that don't require authentication work just fine, but the newer ones always crash on authentication under Windows 8 DP & CP for me.