Grrr setbacks as always

Getting an error that says,

Error: toAppend has no properties
Source File: chrome://slashid/content/E20C0D3A0B5676DBB9395C022DE2F5C4.cache.js
Line: 3285

inside the function

function java_lang_StringBuffer_$append__Ljava_lang_StringBuffer_2Ljava_lang_String_2(this$static, toAppend){
  if (toAppend === null) {
    toAppend = 'null';
  }
  var last = this$static.js.length - 1;
  var lastLength = this$static.js[last].length;
  if (this$static.length > lastLength * lastLength) {
    this$static.js[last] = this$static.js[last] + toAppend;
  }
   else {
    this$static.js.push(toAppend);
  }
  this$static.length += toAppend.length;
  return this$static;
}

which is a GWT-generated function (i.e. I didn’t write it explicitly) which makes it really annoying since it makes it really hard which line of my code causes it, or what causes it all, actually.  And I can’t debug it line-by-line with GWT’s hosted browser cause of the pain-in-the-ass SOP (Single Origin Policy).

Grrrrr.