plugin.php on line 600

[traveltimingsin]

On my website, I'm seeing error below:

"Warning: Parameter 1 to wp_default_styles() expected to be a reference, value given in /home/bots/public_html/traveltimings/wp-includes/plugin.php on line 600"

How to remove this, any steps?

[Ipstenu]

Sadly this means that a plugin you're using is calling wp_default_styles incorrectly.

You'll want to start debugging by turning off all your plugins and see if it goes away.

If you need more help, please post in the forums here: ​https://wordpress.org/support/forum/how-to-and-troubleshooting/

[obenland]

I've gotten that too on some older test installs of mine. It seems to be a PHP 7.1 problem that occurs when core runs the wp_default_styles and wp_default_script actions. In my case it was a 4.5.12 installation on 7.1.8.

Maybe @jrf @johnbillion or @pento can help fix that?

[ocean90]

This is a duplicate of #37772 and was fixed by [38571]. Only 4.7+ is compatible with PHP 7.1.