FlashEEPROM timeout while writing

Ok, I tried the code below:

// Tested on Puck.js
var f = new (require("FlashEEPROM"))();
f.erase();
console.log(f);
f.write(0, 'Hello Flash.');
console.log(E.toString(f.read(0)));

and got:

1v90 Copyright 2016 G.Williams
>Uncaught InternalError: Timeout on jshFlashErasePage
 at line 1 col 31
this.flash.erasePage(this.addr)
                              ^
in function "erase" called from line 1 col 9
f.erase();
        ^
{
  "flash": function () { [native code] },
  "addr": 471040, "endAddr": 475136 }
Uncaught InternalError: Timeout on jshFlashWrite
 at line 1 col 62
...,a.length,a.length>>8,0]),b);b+=4;4!=a.length&&(c=new Uint8A...
                              ^
in function "_write" called from line 2 col 102
...ory!";this._write(a.end,b,c)
                              ^
in function "write" called from line 1 col 26
f.write(0, 'Hello Flash.');
                         ^
ÿÿÿÿÿÿÿÿÿÿÿÿ
=undefined
> 

Am I doing something stupidly wrong or do I have a faulty puck?

Thanks again