Apache proxy_fcgi - Error and PHP Fatal error

Question

I'm getting this error (I attach log) and my domain returns an HTTP 500 error, I haven't changed anything unless I enabled WP-debug in the wp-config file, even if I disable it the problem persists, any ideas on how to solve the problem?

Thanks

[Wed Jan 10 09:45:26.528761 2024] [proxy_fcgi:error] [pid 17529] [client 172.70.39.74:57228] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Undefined constant "\xe2\x80\x98WP_DEBUG\xe2\x80\x99" in /var/www/ricreo/wp-config.php:100\nStack trace:\n#0 /var/www/ricreo/wp-load.php(50): require_once()\n#1 /var/www/ricreo/wp-blog-header.php(13): require_once('...')\n#2 /var/www/ricreo/index.php(17): require('...')\n#3 {main}\n  thrown in /var/www/ricreo/wp-config.php on line 100'
[Wed Jan 10 09:45:52.566957 2024] [proxy_fcgi:error] [pid 15781] [client 172.70.135.68:20814] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Undefined constant "\xe2\x80\x98WP_DEBUG\xe2\x80\x99" in /var/www/ricreo/wp-config.php:100\nStack trace:\n#0 /var/www/ricreo/wp-load.php(50): require_once()\n#1 /var/www/ricreo/wp-blog-header.php(13): require_once('...')\n#2 /var/www/ricreo/index.php(17): require('...')\n#3 {main}\n  thrown in /var/www/ricreo/wp-config.php on line 100'
[Wed Jan 10 10:18:13.720701 2024] [proxy_fcgi:error] [pid 15780] [client 162.158.129.65:24538] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Undefined constant "\xe2\x80\x98WP_DEBUG\xe2\x80\x99" in /var/www/ricreo/wp-config.php:100\nStack trace:\n#0 /var/www/ricreo/wp-load.php(50): require_once()\n#1 /var/www/ricreo/wp-blog-header.php(13): require_once('...')\n#2 /var/www/ricreo/index.php(17): require('...')\n#3 {main}\n  thrown in /var/www/ricreo/wp-config.php on line 100'
[Wed Jan 10 10:18:22.645941 2024] [proxy_fcgi:error] [pid 16218] [client 172.71.147.141:47186] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Undefined constant "\xe2\x80\x98WP_DEBUG\xe2\x80\x99" in /var/www/ricreo/wp-config.php:100\nStack trace:\n#0 /var/www/ricreo/wp-load.php(50): require_once()\n#1 /var/www/ricreo/wp-blog-header.php(13): require_once('...')\n#2 /var/www/ricreo/index.php(17): require('...')\n#3 {main}\n  thrown in /var/www/ricreo/wp-config.php on line 100'
[Wed Jan 10 10:18:23.453478 2024] [proxy_fcgi:error] [pid 15781] [client 172.71.150.162:26612] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Undefined constant "\xe2\x80\x98WP_DEBUG\xe2\x80\x99" in /var/www/ricreo/wp-config.php:100\nStack trace:\n#0 /var/www/ricreo/wp-load.php(50): require_once()\n#1 /var/www/ricreo/wp-blog-header.php(13): require_once('...')\n#2 /var/www/ricreo/index.php(17): require('...')\n#3 {main}\n  thrown in /var/www/ricreo/wp-config.php on line 100'
[Wed Jan 10 10:18:34.435875 2024] [proxy_fcgi:error] [pid 15782] [client 162.158.129.64:43242] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Undefined constant "\xe2\x80\x98WP_DEBUG\xe2\x80\x99" in /var/www/ricreo/wp-config.php:100\nStack trace:\n#0 /var/www/ricreo/wp-load.php(50): require_once()\n#1 /var/www/ricreo/wp-admin/admin.php(34): require_once('...')\n#2 /var/www/ricreo/wp-admin/index.php(10): require_once('...')\n#3 {main}\n  thrown in /var/www/ricreo/wp-config.php on line 100'
[Wed Jan 10 10:20:10.847054 2024] [proxy_fcgi:error] [pid 17529] [client 34.76.96.55:40308] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Undefined constant "\xe2\x80\x98WP_DEBUG\xe2\x80\x99" in /var/www/ricreo/wp-config.php:100\nStack trace:\n#0 /var/www/ricreo/wp-load.php(50): require_once()\n#1 /var/www/ricreo/wp-blog-header.php(13): require_once('...')\n#2 /var/www/ricreo/index.php(17): require('...')\n#3 {main}\n  thrown in /var/www/ricreo/wp-config.php on line 100'

Answer 1

The error message indicates that the quotation marks around WP_DEBUG are not standard single or double quotes. They appear to be curly quotes, which PHP does not recognize as valid syntax for string delimiters.

Replace the curly quotes (‘ or ’) with standard single quotes (') or double quotes (").

This error is a common issue when text editors replace standard quotes with curly quotes, especially if you copy the code from some tutorial on the net that does not have standard formatting for codes.