my m13 is doing the exact same thing as the OP has stated. I have sent Line 6 a message but I'm not holding my breath for a solution. Does anyone have a solution for this year old thread??
Upon powering up fx1 and fx2 are lit, with the text "flash update mode waiting command" showing. no buttons or knobs are functional. I have not attempted an update or hooked this up to any midi or USB or anything... essentially out of the box. anyone?