Default what is problem if drm keys are lost?

i have recently unlock boot loader of xperia u but without ta backup
and then i relock the boot loader of xperia u so my question is what application
not work after lost of drm keys and plz tell is bravia engine on xperia u work or not
after relocking of boot loader and how i check is bravia engine is work or not
plz tell me
i check my drm key status it says
MARLIN [UNKNOWN ERROR] [ACTIVE]
WMLA [[UNKNOWN ERROR] [NOT ACTIVE]
IS ANY METHOD TO BACK THIS KEY AGAIN I HAVE NO TA BACKUP
IF ANY METHOD PRESENT PLZ TELL ME
SHOULD I GO SONY CARE CENTRE TO BACK DRM KEYS
I KNOW THIS JOKE BUT IS ANY CHANCE TO BACK THIS KEY VIA CARE CENTRE
PLZ TELL ME