Knowledge Base

Site Preview button leads to “Error: Invalid URL was requested.” being showed in Plesk UI

The Site Preview button displays an error instead of showing site content:

Invalid URL was requested.
Server OS is Ubuntu 20.04 or 22.04.
Manually replacing http by https in the preview link does make the site preview content to be displayed.
There is no location ^~ /plesk-site-preview/ directive under listen IP_ADDRESS:443 ssl in /etc/nginx/plesk.conf.d/server.conf:

# grep "location ^~ /plesk-site-preview/" /etc/nginx/plesk.conf.d/server.conf
#

This is the Plesk bug PPPM-14141 which will be solved in future Plesk updates.

Until the bug be fixed, as workaround:

Log in to Plesk via https://<server-IP-or-hostname>:8443, e.g. https://203.0.113.2:8443.
Navigate to Tools & Settings > Customize Plesk URL
Select No custom URLs. Only https://<server-IP-or-hostname>:8443
Save the changes

Connect to the Plesk server via SSH.
Run the command below to set no custom URLs leaving Plesk accessible via default port 8443 only:

# plesk bin admin --disable-access-domain