Warning: Cannot modify header information functions.php and wp-includes

[goodsky]

Hi

I’ve just migrated to a new host and am getting the following warning

Warning: Cannot modify header information - headers already sent by (output started at /home/customer/www/noosahealth.com.au/public_html/wp-content/themes/x-child/functions.php:40) in /home/customer/www/noosahealth.com.au/public_html/wp-includes/pluggable.php on line 1296

I’ve cleaned the functions.php file but not sure what to do with the wp-includes file. Please advise

[tristup]

Hi @petomi14,
Thanks for reaching out.

There might be a few different reasons for this issue, I would suggest you troubleshoot with a few of the common issues:

1. CSS/JS Customization
2. Testing for Plugin conflict
3. Child Theme Issue

If you have not done yet, please activate the parent theme to check whether the issue is with the Child Theme or not.
If that resolves the issue, that means the child theme is erroneous, in that case, I would suggest you hire a developer for further fixation.
Please remember that we don’t offer any support or investigation for the modified child theme and issue(s) related to it.

If you find that the issue still exists after activating the Parent theme, please copy your site to the staging server](https://www.wpbeginner.com/wp-tutorials/how-to-create-staging-environment-for-a-wordpress-site/) so we could troubleshoot freely without breaking your live site.
And give us access in the secure note including:

– WordPress Site URL & Admin URL
– WordPress Admin username / password

To create a secure note, click the key icon underneath any of your posts.

Thanks