Akismet API page blank, letting all spam through

As of 2 days ago, i’m getting all comments marked as “Pending Spam Review” and Akismet appears to have stopped working. Selecting Akismet on the dashboard gives me a blank page. JetPack 3.0.2

I’ve just cleared out 165 spam comments received today by hand.

I don’t have short Akismet plugin cited as the problem in a recent note. I’m using the Typo theme on this site (www.ianwaring.com). Akismet is the only plugin active on the site. Any ideas?