Layout Error, Function "txt" not found!

I'm seeing a similar error to that described in RaoulDuke's post.

When I enter sample code from the layout tutorial:

var Layout = require("Layout");
var layout = new Layout( {
  type:"txt", font:"6x8", label:"Hello World"
});
g.clear();
layout.render();

I get the following error:

>Uncaught Error: Function "txt" not found!
 at line 2 col 373
...c)h[k.type](k)})}};h[d.type](d)
                              ^
in function "layout" called from line 4 col 152
...ct.h-f.h>>1));this.layout(f)
                              ^
in function "update" called from line 1 col 203
....updateNeeded&&this.update();var b=g,f={"":function(){},txt:...
                              ^
in function "render" called from line 1 col 15
layout.render();
              ^

with version 2v16.1 (both on the emulator and my BangleJS 2). I've turned off "Shorten variable names" in the emulator as suggested by the earlier post.

If I run it as an application a 2nd time on the device, it works as expected. What is different?