Knowledge Base

All websites are down with 502 Bad Gateway error: apache2 or httpd is not running

Symptoms

All websites on the Plesk server are showing a 502 Bad Gateway error while opened in a browser
Attempts to start Apache and Apache configuration tests fail with an error that is similar to the following:

AH00526: Syntax error on line 51 of /etc/apache2/plesk.conf.d/vhosts/example.com.conf:
SSLCertificateFile: file '/opt/psa/var/certificates/cert1Ape62' does not exist or is empty
The following error is shown in the Plesk GUI:

New configuration files for the Apache web server were not created due to the errors in configuration templates: nginx: [emerg] BIO_new_file("/usr/local/psa/var/certificates/cert1Ape62") failed (SSL: error:02001002:system library:fopen:No such file or directory:fopen('/usr/local/psa/var/certificates/cert1Ape62','r') error:2006D080:BIO routines:BIO_new_file:no such file) nginx: configuration file /etc/nginx/nginx.conf test failed . Detailed error descriptions were sent to you by email. Please resolve the issues and click here to generate broken configuration files once again or here to generate all configuration files. See the details in Configuration Troubleshooter
That SSL certificate that is reported in the error message has zero size:
- For RHEL-based OS (CentOS, CloudLinux, RedHat:
  
  # ls -l /usr/local/psa/var/certificates/cert1Ape62
  ...
  -r-------- 1 root root 0 Mar 24 12:26 /opt/psa/var/certificates/cert1Ape62
- For Debian-based OS (Debian, Ubuntu):
  
  # ls -l /opt/psa/var/certificates/cert1Ape62
  ...
  -r-------- 1 root root 0 Mar 24 12:26 /opt/psa/var/certificates/cert1Ape62
The Plesk web server reconfiguration utility fails with an error that is similar to the following:

# /usr/local/psa/admin/bin/httpdmng --reconfigure-domain example.com
...
ERR [panel] Apache config (14972022740.47990300) generation failed: Template_Exception: Syntax error on line 51 of /etc/httpd/conf/plesk.conf.d/ip_default/example.conf:
SSLCACertificateFile: file '/usr/local/psa/var/certificates/cert1Ape62' does not exist or is empty
Repairing files system permissions with the plesk repair utility results in an error that is similar to the following:

# plesk repair fs -y -v
Checking Linux system files ......................................... [OK]
Checking virtual hosts' file system
There are incorrect permissions on some items in the system
directory for the domain 'example.com' .......................... [ERROR]
- Failed to stat
/var/www/vhosts/system/example.com/conf/webalizer.conf: No
such file or directory
Repairing incorrect permissions ................................. [FAILED]
- openat 'webalizer.conf' failed: No such file or directory
Failed to open safely
/var/www/vhosts/system/example.com/conf/webalizer.conf: No
such file or directory
All websites on the server are not accessible, while showing a browser error that is similar to the following :

ERR_CONNECTION_REFUSED

Cause

The SSL certificate file that is reported in the error message is missing or is corrupted, due to which it has an improper size or is not found at all.