Apache fails to start during upgrade/installation: Invalid command 'php_value', perhaps misspelled or defined by a module not included in the server configuration

Renan Poss Moreira

Updated January 13, 2026 19:00

kb: bug kb: fixed Plesk Obsidian for Linux ABT: Group B

Applicable to:

Apache fails to start during Obsidian upgrade/installation. The error is logged in /var/log/plesk/install/autoinstaller3.log:

CONFIG_TEXT: Invalid command 'php_value', perhaps misspelled or defined by a module not included in the server configuration
httpd -t shows a similar error:

# httpd -t
httpd[13923]: AH00526: Syntax error on line 31 of /etc/httpd/conf.d/php.conf:
httpd[13923]: Invalid command 'php_value', perhaps misspelled or defined by a module not included in the server configuration
OS PHP is used with version 5.4:

# php -v
PHP 5.4
<IfModule mod_php5.c> tags in /etc/httpd/conf.d/php.conf are removed after upgrade/installation leaving the following directives without enclosing tags:

CONFIG_TEXT: php_value session.save_handler "files"
php_value session.save_path "/var/lib/php/session"
Tools & Settings > Apache Web Server Settings > php5 is disabled.

Product issue:

#PPP-45093 "On CentOS 7 servers, Apache no longer fails to start after installing PHP from OS vendor via Plesk Installer."
Fixed in:
- Plesk Obsidian 19 November 2019 (Linux)

Please consider updating your server:

If update is not possible for some reason you may try the following

workaround

Connect to the server via SSH.
As a workaround comment out with "#" the php_value directives:

# sed -i 's/php_value/#php_value/g' /etc/httpd/conf.d/php.conf
Restart Apache:

# systemctl restart httpd.service