Miele silver moon cannister vacuum dust compartment power switch

\015 We have a Miele Silver moon S558 canister vacuum.The vacuum will not turn on due to dust compartment issues. If the dust compartment is completely closed it will not operate. If you open it even partially it will operate. i am assuming that there is a issue with the dust bag. But is is only partially full. can you help?\015 – Miele Vacuums