Some pages of the web-site returns 503 error: child exited on signal 11 (SIGSEGV)

Symptoms

• Some pages or subdirectories on website return 503 error code. For example, http://example.com/test/:

  PLESK_INFO: Service Unavailable

• The following errors can be found in the php-fpm error log at /var/log/plesk-phpXX-fpm/error.log:

  PLESK_INFO: NOTICE: [pool example.com] child 19845 started
  WARNING: [pool example.com] child 12894 exited on signal 11 (SIGSEGV) after 933.407729 seconds from start

• The following errors can be found in the /var/log/syslog log file:

  PLESK_INFO: server52 kernel: [5382244.017824] php-fpm[23589]: segfault at 7ffee4e79e98 ip 0000000000660b90 sp 00007ffee4e79ea0 error 6 in php-fpm[400000+3b8000]
  server52 mysqld: 180107 19:29:26 [Warning] Aborted connection 10030808 to db: 'db_name' user: 'user_name' host: 'localhost' (Got an error reading communication packets)

Cause

Incompatibility between the PHP interpreter and website code

Resolution

Contact the plugin provider/application developers in order to fix the issue.