I tried to reactivate the plugin. I'm not getting a 500 error any more but I still can't get an API key and whenever I try to enter my email address for notifications and set the protection level, I get a message saying:
Please reload this page
You selected a config option that requires a page reload. Click the button below to reload this page to update the menu.
And when I click the "Reload page" button, I am just taken back to the same Wordfrence Options page with the same problem that keeps recurring .