After upgrading from PHP version 7.0 to 7.1 on my WordPress website hosted with DreamHost, I received the error message below above the header on my website.
Warning: Parameter 2 to wp_hide_post_Public::query_posts_join() expected to be a reference, value given in /home/xyz_vps/nafzinger.com/wp-includes/class-wp-hook.php on line 298
The solution
If you’re not using the WP Hide Post plugin, make note of the error message, it should give you a hint what plugin is causing the issue, in the case above, my hint was Parameter 2 to wp_hide_post_Public::query_posts_join(). You can also just disable the problematic plugin.
In my case, the error was caused by a bit of code in the WP Hide Post plugin. I fixed it by connecting to my server via SFTP, then navigating to the WP Hide Post plug-in directory, as shown below.
/wp-content/plugins/wp-hide-post/public/class-wp-hide-post-public.php
- Open class-wp-hide-post-public.php and do a search for &$.
- Remove the all & that appear in front of the $ and save your file.
- Refresh your website and the problem should be fixed.
- If you’re using a caching plugin you may need to force purge your cache and try again.
Apparently, PHP 7.1 doesn’t like & in front of $query parameters in functions.
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