Chantal van Laere , If at all possible find the receipt, if bought on credit card there may be a history of purchase. Some things that could cause the smell, is a bad switch or connection arcing/melting, belt slipping on drive(if equipped),failing capacitor of overheated resistor, perhaps main PCB. The food processor/blender will have to come apart to see what components,etc. may be failing and to see exactly what is going on(link below is not your exact model but may give an idea of how to disassemble to view components).. If you google Kenwood fpm250 burning rubber smell you will see that a lot of people had this issue. Also find your user manual link below. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
https://www.youtube.com/watch?v=5-lEDWuH...
http://www.kenwoodworld.com/Global/Instr...