Cobra Forum

Question: Unable to access example.com website on the particular PHP version: 503 Service Temporarily Unavailable


Applicable to:

• Plesk for Linux

Symptoms

• Unable to access the example.com website on the particular PHP version:

503 Service Temporarily Unavailable

• In an attempt to switch PHP version in Plesk > Domains > example.com > PHP Settings the process fails with the following error:

Error: phpinimng failed: ERROR:fpm_util:check failed service plesk-phpXX-fpm socket /run/plesk/plesk-phpXX-fpm.sock reason [Errno 111] Connection refused: '/run/plesk/plesk-phpXX-fpm.sock'

• It is not possible to start affected PHP service with the error below in /var/log/plesk-phpXX-fpm/error.log file:

ERROR: An another FPM instance seems to already listen on /var/www/vhosts/system/example.com/php-fpm.sock
ERROR: FPM initialization failed `/var/www/vhosts/system/example.com/php-fpm.sock` failed

Cause

The /var/www/vhosts/system/example.com/php-fpm.sock file is corrupted.


Resolution

1.Log into the server via SSH.

2.Remove the /var/www/vhosts/system/example.com/php-fpm.sock file:

# rm -rf /var/www/vhosts/system/example.com/php-fpm.sock

3.Log into Plesk.

4.Go to Domains > example.com > PHP settings.

5.Switch PHP version to another:

(https://pix.cobrasoft.org/images/2025/12/29/phpvers.png)

6.Scroll down and press the Apply button.

7.Switch PHP version back to the required.

8.Scroll down and press the OK button to apply the changes.