Domain's PHP function is not available: function() has been disabled for security reasons

Vincent Lauton

Updated September 30, 2025 20:57

Plesk for Linux kb: technical ABT: Group B

Applicable to:

Plesk for Linux

Symptoms

An error like this one appears in Domains > example.com > Logs, or on the website

Note: <function_name> is a placeholder and will be different in the actual error

Got error 'PHP message: PHP Fatal error: Uncaught Error: Call to undefined function <function_name>() in /var/www/vhosts/example.com/httpdocs/test.php:3\nStack trace:\n#0 {main}\n thrown in /var/www/vhosts/example.com/httpdocs/test.php on line 3'

Cause

The PHP function from the error is disabled in php.ini

Resolution

Warning: These steps don't work with PHP-FPM (global settings override them); they only apply to FastCGI.

Enable the disabled functions in the PHP configuration.

Individual Domain

Log into Plesk
Go to Domains > example.com > PHP Settings
Remove the desired function from disable_functions
Press OK

If there's no section called disable_functions, add disable_functions="" to Additional directives instead.

All Domains (Plesk Panel)

Log into Plesk
Identify the affected PHP handler in Domains > example.com > PHP
Go to Tools & Settings > PHP Settings > Affected PHP version > php.ini
Find disable_functions and remove the function from the error
Press OK to save the changes

All Domains (CLI)

Connect to the server via SSH
Identify the affected PHP handler with this command

Note: Replace example.com with the website from the error

# plesk db "SELECT d.name,h.php_handler_id FROM domains d JOIN hosting h on h.dom_id=d.id WHERE name='example.com'"
Edit the handler's php.ini

Note: Replace X.X with the version from Step 2

# vi /opt/plesk/php/X.X/etc/php.ini
Find the line with disable_functions and delete the function from the error
Restart the PHP service:

# systemctl restart plesk-phpXX-fpm