Cycle race track lap counter

@Gordon I'd like to have a method to do a reset "in the field", meaning starting everything new when I have to.

What is working is calling my reset() method via commandline.
What does not work is calling it through a handler after a button was pressed.

The method does this:

  reset: function() {
    console.log('reset');
    if(!Flash.s.write(Flash.NAME, [CONST.LAP_DATA_SIZE], 0, 1 + CONST.LAP_DATA_SIZE * CONST.LAPS_STORAGE)) {
      throw new Error('could not reserve storage');
    }
    Flash.pos = 0;
  },

manual call:

>Flash.reset()
reset
=undefined

through handler:

reset
Uncaught Error: Unable to find or create file
 at line 1 col 114
...ATA_SIZE*CONST.LAPS_STORAGE))throw new Error('could not reserve stor...
                                      ^
in function "reset" called from line 1 col 15
a&&Flash.reset(),Object.keys(this.macs).­forEach(c=>{const d=this.macs[c];...
                           ^
in function "init" called from line 1 col 122
...tons.BTN_MID]&&(Race.init(!0),ErrorLo­g.log=[]),this.objects.forE...
                                  ^
in function "wakeup" called from line 1 col 16
a?Power.wakeup():Power.sleep()
               ^
in function "onOff" called from line 1 col 37
...N?Buttons.onOff(a,b.state==0):Buttons­.event(a,b.state==0)
                                ^
in function called from system