Do you need to specify an alternate source path? One or more installation selections are missing source files on the destination server.
This is quite annoying and it took my also a while to figure it out the first time. In Windows 2008 you din’t need your Windows DVD anymore to add features and roles. In Windows 2012 they have changed it to save storage. This isn’t actually bad but I don’t understand why they made the installation wizard so complicated, so that you can’t figure it out on your own.
The solution to this error is somewhere at the begining of the installation. You need to choose Specify Alternate Source Path and enter your Windows 2012 dvd or load the image of it:
Specify Alternate Source Path