Add the following code before you call loadString():
htmlLoader.placeLoadStringContentInApplicationSandbox = true;
By default, content added via loadString() is not in the application security sandbox (and it cannot load images from the application directory). By setting this property to true, loadString() content is placed in the application security sandbox.
For more information, see the property's description in the language reference:
3 Hours I was looking around the internet before I posted here to try and get that to work haha, I knew it would be as simple as 1 little line to fix it all . Thanks very much!
Glad to help.