Plesk error: Invalid command ‘ProxyTimeout’

Symptoms

1. Plesk shows the following error:

   AN00526: Syntax error on line 112 of /etc/httpd/conf/plesk.conf.d/server.conf: Invalid command 'ProxyTimeout', perhaps, misspelled or defined by module not included in the server configuration.

2. Configuration errors in Plesk database like:

   # plesk db -e"select * from Configurations where status='error'G"
   httpd: Syntax error on line 56 of /etc/httpd/conf/httpd.conf: Syntax error on line 2 of /etc/httpd/conf.modules.d/00-proxy.conf: Cannot load modules/mod_proxy.so into server: /etc/httpd/modules/mod_proxy.so: file too short
   Cannot load modules/mod_proxy.so into server: /etc/httpd/modules/mod_proxy_fcgi.so: file too short

3. Some websites do not work:

   File Not found

4. Some websites show webmail pages instead of web content.
5. PHP files are downloaded by the web browser instead of being opened.

Cause

The mentioned Apache modules are corrupted.

Resolution

1. Connect to the server via SSH

2. Create a backup of the corrupted files:

# mv /etc/httpd/modules/mod_proxy.so{,.old}
# mv /etc/httpd/modules/mod_proxy_fcgi.so{,.old}

3. Reinstall the httpd package to fix the files:

# yum reinstall httpd