aquasteam 6sense washing machine f:26 error?

i had a load of washing in the machine, during the cycle the machine kept stopping and the start button would flash so i kept pushing it and at nine minutes to go it gave up and flashed f:26, i thought the filter was blocked so i turned the machine off and unscrewd the filter to get a nice big flud of water rushing at me, the door did open to allow me to get my washing but now i cannot get rid of the f:26 error code. i have tried everything please help. thanks