OpenID Error: Fatal error: Call to a member function needsSigning()

Hi,
The OpenID itself provided by the plugin seems to work according to https://openidenabled.com/resources/openid-test/checkup/start?openid_url=https://www.ispithotfire.com

but when I try to login with it on my site or others, that is where the errors occur.

Fatal error: Call to a member function needsSigning() on a non-object in /home/…/openid/Auth/OpenID/Server.php on line 1495

I can’t add my site to the “Your Verified OpenIDs” section in my WP either.

I’m not sure what this error means, anyone have any insight?

(site is https://www.ispithotfire.com)