PHP Warning: Cannot modify header information

May I know what is your PHP version ?

8.1

Can you please help? My Debug.log is filled with thousands of these PHP warnings.

Hi,

yes, I have reported this to devs for further investigation

best regards,

Sometimes this one appears in between the other warning:

[09-Nov-2022 16:54:38 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /home/mymoissanite/public_html/staging/wp-cron.php:30) in /home/mymoissanite/public_html/staging/wp-content/plugins/sitepress-multilingual-cms/classes/request-handling/class-wpml-language-per-domain-sso.php on line 123

Hence, it may have to do with WPML? All versions are updated to latest.

Hello. Could you provide any updates?

I get the same problem. Php version 8.1

PHP Warning: Cannot modify header information – headers already sent by (output started at /home/****/public_html/wp-cron.php:30) in /home/*****/public_html/wp-content/advanced-headers.php on line 35

FYI: advanced-headers.php file is generated by really simple ssl PRO

I use latest litespeed plugin ( version 5.3.2 ) and in cpanel: 6.0.12 (build 13)

Please advise.

UPDATE: After further investigation it seems this is a long reported bug: https://bugs.php.net/bug.php?id=75946&edit=2

The problem will only show if you are running wp-cron through a wget/curl request. If you are instead using a local cron job and calling it directly through php, there is no request so no headers and no issue.

• This reply was modified 1 year, 10 months ago by Robert22.

Hi @sebastiaanvaz

I just checked with our support team regarding this issue. Basically we could not reproduce this purposefully at this moment. I saw different users were complaining about this as well in the past topics. To help us figure this out, could you please open a ticket by emailing to [email protected] with some further details? We may need to work closer with you to find out the root cause.

Please remember to reference this topic and ask to assign your ticket to Abe. I will check into this further from there.

I can confirm @robert22 findings. Running WP 6.1, PHP 8.1, LSCWP 5.3.2.

This issue indeed only pops-up when running cron via the server with wget/curl. Is there any progress on this issue?

this issue will be patched in next release ??

Great! Thanks for the update!