Deprecated: Hook custom_css_loaded is deprecated since version jetpack-13.5!

Hello there @nonfascist

You can find more information regarding this particular deprecation notice here:
https://jetpack.com/support/custom-css/

In short, starting version 13.7 (scheduled for August 2024), Jetpack will no longer support the Custom CSS feature.

1. If your site has WP_DEBUG enabled, deprecated features and warnings like these are printed out when the page loads. For a production site, it is recommended to have WP_DEBUG disabled to prevent system debug messages from being shown to your users. More information about how to control this value can be found here: https://jetpack.com/blog/wp-config-php/

I would recommend ensuring WP_DEBUG is false when in production, and true when in development.

2. You can check if your site is using Jetpack’s Custom CSS feature by visiting Jetpack → Settings → Writing in your site’s dashboard. Scroll down to the Theme Enhancements section and review the Enhance CSS customization panel option.

If the custom CSS feature is enabled, I would recommend turning it off to remove the deprecation warning and have your site ready for the eventual update 13.7 which will remove the feature. You can move any custom styles to the Appearance → Customize panel in your WordPress admin dashboard (if you have used SCSS or LESS to write these styles, you will need to convert them to CSS before moving them over).

I hope this information is useful, and please let me know if you have additional questions regarding this issue, or anything else Jetpack!

Thank you, @njweller .

Your advice in number 2 worked when I toggled the Custom CSS Enhance CSS customization panel switch to the off position.

At the same time, I have no idea what Custom CSS styles are being used on my website or how to find them. I don’t know how to find them or what they are. Much less would I know how to convert them to CSS before moving them over.

The link that you shared with us about the deprecation notice for Jetpack brings me to a page full of technical language that goes mostly over my head. I wish that I knew what it all meant!

Taha! Thanks anyways. I have appreciated the site stats features of Jetpack and will hopefully get to continue using the plugin.

Adam

I totally empathize with that @nonfascist!

The good news is that in most cases, Jetpack and WordPress will have already taken care of moving any custom styles over for you, and simply turning off the feature as you have just done is all that needs to be done ?? ??

I will provide more technical mumbo jumbo below, just for good measure:

You should be able to see if you are using any custom CSS by visiting this page on your site:
/wp-admin/customize.php?autofocus[section]=custom_css

If there is any content in the text box on the bottom left of the screen, that is your custom CSS which has already been moved over for you. If there is no content here, or there is CSS, then we are good to go!

The cases that need more technical intervention (i.e. “converting to CSS”) is when the custom styles were written with a different styling language such as LESS or SCSS. The deprecated Jetpack feature included support for writing CSS with different languages, which WordPress does not include.

If you do have content in this box, and are unsure if you need to take any additional steps, feel free to share the styles here and I can let you know if they need conversion/convert them to CSS on your behalf.

Cheers!