Why has my Magimix 4000 locked up?

After having used it as normal, the bowl of my Magimix 4000 has become locked to the base containing the motor. I have tried hot water, as well as an ice compress, but it will not budge. I have had the machine for many years and it has never displayed a safety lock feature before, if that is what it is. It still works fine, but I cannot clean it. Any suggestions?