Many websites failed to open on the Plesk server: Error 502: Connection refused while connecting to upstream

Aleksandar Stoev

Updated April 07, 2026 08:32

Plesk for Linux kb: technical

Applicable to:

Plesk for Linux

Symptoms

Error in Plesk UI:

PLESK_ERROR: New configuration files for the Apache web server were not created due to the errors in configuration templates: Can not restart web server: apache_control_adapter[4921]: Apache is down, start it instead of graceful apache_control_adapter[4921]: apache_action(graceful): invoke_httpd_action failed, trying second time apache_control_adapter[4921]: Apache is down, start it instead of graceful INFO: [Thu Jan 29 08:15:11 EET 2026]: Service: apache, Action: start Trying to start service httpd... activating ***** problem report ***** Warning: start service httpd failed /usr/local/psa/admin/sbin/pleskrc execution failed: Job for httpd.service failed because the control process exited with error code. See "systemctl status httpd.service" and "journalctl -xeu httpd.service" for details. See the details in Configuration Troubleshooter. 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.
Error in website logs:

CONFIG_TEXT: connect() failed (111: Connection refused) while connecting to upstream
The httpd service fails to start:

CONFIG_TEXT: Jan 29 10:13:14 srv (httpd)[46061]: httpd.service: Failed to set up mount namespacing: /usr/local/psa/handlers/spool: No such file or directory
Jan 29 10:13:14 srv (httpd)[46061]: httpd.service: Failed at step NAMESPACE spawning /usr/sbin/httpd: No such file or directory

Cause

The directories /usr/local/psa/handlers and /usr/local/psa/handlers/spool are missing. This behavior has been identified as bug with ID: PPPM-15328.

Resolution

The issue has been fixed in Plesk Obsidian 18.0.77.1. If your server is running an older version, please update your Plesk server to the latest build.

Alternatively, the following workaround can be applied

Connect to the Plesk server via SSH.
Create all necessary directories:

# mkdir -p /usr/local/psa/handlers/spool
# chmod 755 /usr/local /usr/local/psa /usr/local/psa/handlers
# chmod 700 /usr/local/psa/handlers/spool
# mkdir -p /usr/local/psa/handlers/before-local
# mkdir -p /usr/local/psa/handlers/before-queue
# mkdir -p /usr/local/psa/handlers/before-remote
# mkdir -p /usr/local/psa/handlers/hooks
# mkdir -p /usr/local/psa/handlers/info/p
Start the httpd service:

# systemctl start httpd
Run the Plesk repair:

# plesk repair all -y

Note: If you have a large number of sites, this may take time and may also cause short-term site downtime while the configuration files are created.