It looks like this was being caused by .htaccess rewrite rules on my client’s server being configured to direct certain traffic to an old subfolder WordPress installation, which didn’t include the plugin. In any case, it’s now resolved.
It looks like this was being caused by .htaccess rewrite rules on my client’s server being configured to direct certain traffic to an old subfolder WordPress installation, which didn’t include the plugin. In any case, it’s now resolved.