Plesk Home page shows: nginx: [emerg] a duplicate default server for 2001:db8:f61:a1ff:0:0:0:80

Symptoms

• Plesk Home page shows the next error:

  PLESK_ERROR: New configuration files for the Apache web server were not created due to the errors in configuration templates: nginx: [emerg] a duplicate default server for [2001:db8:f61:a1ff:0:0:0:80]:443 in /etc/nginx/plesk.conf.d/ip_default/example.com.conf:7 nginx: configuration file /etc/nginx/nginx.conf test failed.

• The following command fails with the same error:

  # plesk repair web example.com

• There is a configuration file with the same IP 2001:db8:f61:a1ff:0:0:0:80 for a non-existing domain:

  # grep -Rl "2001:db8:f61:a1ff:0:0:0:80" /etc/nginx/*
  /etc/nginx/plesk.conf.d/ip_default/example1.com.conf

• Or the following command shows that there is an orphan configuration file:
  # plesk repair web -n
  Checking web server configuration. Please wait

  Unknown file: /etc/nginx/plesk.conf.d/ip_default/example1.com.conf . [ERROR]

Cause

Domain example1.com was removed from Plesk but its configuration file remained.
For this reason, a new configuration file for example.com can not be created.

Resolution