I’m having the same issue, running WordPress 2.3.2, PHP 5.2.5, and OpenID 2.1.2: when I attempt to activate, I get a fatal error with no text.
I’m happy to poke around and work on debugging this myself, but I’m not sure where to look for a more detailed error message. (I do see that it’s definitely not going to the Apache error logs, for example.)
I’m happy to work with someone to debug this, or to receive advice on where to look for more details.
