I am using the latest, PR16 version.
Following up on this case I did a little test, opened a page capable of detailing some of the capabilities and limitations of the actual browser in this particular embedded browser module.
You can view the results here:
http://html5test.com/s/a6248640748a8445.html
Anything that might give a clue as to why it's returning null for the krpano.webgl?
Or any other idea/suggestion on what should I test further? Like I mentioned earlier, get.webgl.org tells me I have webgl (as does the html5test site), and I'm using the latest krpano version. Something's fishy here :)
EDIT: I actually tried loading the makescreenshot example from here on krpano.com into the browser module and everything works fine there. Very strange, now it's a matter of me trying to find out what is the difference between your example and my code...