Found a solution! Just go to the playback devices and properties. Go the advanced tab and play with the options, the one that worked for me was 16 bit 48000 dvd quality!
I have the same issue, last night I Installed windows 10 and my podxt doesn't work. I get "Failed to play sound test" too. BUT when I go to cubase everything works ok within the program but when I exit there's no sound on windows. Any thoughts?