Warning: Missing argument 2 for wpdb::prepare()

Same here. Something is wrong with Akismet plugin. Found another thread with the same issue – https://www.ads-software.com/support/topic/akismet-causing-wp-dbphp-problem-after-35-upgrade

Me too !

And me four.

I’m told by WordPress support to refer you to https://core.trac.www.ads-software.com/changeset/22429

The good news is that this seems to just be a warning so far — things do seem to be working normally otherwise.

If the warning is really bugging you, you can add an empty array argument as shown here: https://www.skyebook.net/blog/2012/12/wpdbprepare-warning-in-wordpress-3-5/

I just logged in back to my WordPress dashboard and this warning is no longer appearing on comments page. Strange!