I own a skoda superb l&k, and suddenly the Bluetooth stopped working and wherever I try to turn it it on a message stating " Bluetooth could not be switched on " pops up 

Will need checking for fault codes, could be there is an internal failure of the Bluetooth antenna or such.

 

could be something more basic like a hard reset or complete wipe and reset will sort the issue 

 

personally I would start with a fault code scan to see if it finds anything