Sorry, looks like a couple of the more recent versions of the extension had some metadata that trips up older versions of Stencyl when trying to find the latest available version of the extension. I've fixed up the metadata so you should be able to download it now.
Since you opened the sample game without having the extension, you may have lost some of the design mode blocks from the test scene (if you saved it). In that case, delete the sample game and import it again. Losing blocks like this is no longer an issue in the more recent private builds of Stencyl, in case you feel inclined to update.
That's correct output for the sample game. You need to add /sdk.html?testAds=true to the end of the url that Stencyl opens when you test an html5 game in order to test crazygames functionality.
Not everything can be tested locally. Some things (like happy time) need to be tested on their servers.