Anyone know what to do with Error Message "Err" ?

Loads of answers for error messages with numbers but what do I do to get rid of the message "Err" - the manual is totally useless on this one! The machine has this error but not in current cycle, anything ive tryed have not worked llike turning off machine , opening /closing door, pressing every button on the display to try reset it , but no joy , machine wont work/start by pressing anything - just a constant beep with " Err" Many thanks