I would live to get this fixed for you, but I am going to need more information about your setup. That way, I can attempt to replicate the issue on our servers.
What plugins are you using the with? What fields are you using in your forms?
Same here: Warning: Cannot modify header information – headers already sent by (output started at /home/XXXX/public_html/wp-content/plugins/acf-frontend-form-element/main/frontend/fields/general/class-upload-file.php:1091) in /home/XXXX/public_html/wp-login.php on line 504
Php: 8.3 (but I tried also with 8.0), Elementor pro (latest version), WordPress 6.5.3
Same here. Cannot load the admin page at all.
Warning: Cannot modify header information – headers already sent by (output started at /home/onewood/www/www/wp-content/plugins/acf-frontend-form-element/main/frontend/fields/general/class-upload-file.php:1091) in /home/xxx/www/www/wp-admin/includes/misc.php on line 1439
Warning: Cannot modify header information – headers already sent by (output started at /home/onewood/www/www/wp-content/plugins/acf-frontend-form-element/main/frontend/fields/general/class-upload-file.php:1091) in /home/xxx/www/www/wp-includes/functions.php on line 7096
Warning: Cannot modify header information – headers already sent by (output started at /home/onewood/www/www/wp-content/plugins/acf-frontend-form-element/main/frontend/fields/general/class-upload-file.php:1091) in /home/xxx/www/www/wp-admin/admin-header.php on line 9
WordPress 6.5.3
PHP 8.1.28
I have done much testing, but have not been able to reproduce this issue. Can you please go through the steps of what you did so that I can try and reproduce this error on my servers? Unfortunately, the error message you provided doesn’t give me enough information….
I have the same problem. Live site been working fine for many months. Suddenly user can’t login in as Editor. If I try to login as admin I get this error message when I turn on error logging.
I apologize for this bug, it seems that before deploying 3.21.2, there was some white space after the closing php tag of one of the plugin files. I have no idea why this wasn’t caught during testing, but I will investigate and make sure that this is kind of issue is always caught from now on.
Version 3.21.3 fixes this issue