I also had the NaCl error, but typed: chrome://components
into the addressbar, then clicked on the "search for updates" under "pnacl".
After Update it works.
However, I get a black screen (like some others) when the status is "running",
strangely enough following the links that were posted, then don't work, it
complains that it's not "Desktop Chrome", maybe a win8/metro thing ?
But still - a big thank you for your hard work !!