The website/site preview shows 500 Internal Server Error: /etc/sw-cp-server/conf.d/trusted_ips.inc: No such file or directory

Symptoms

1. The website/site preview is unavailable:

500 - Internal server error

2. The following error is shown in /var/log/sw-cp-server/error_log log file:

[error] 23706#0: *4926 lua entry thread aborted: runtime error: access_by_lua(plesk_site_preview.conf:15):2: bad argument #1 to 'lines' (/etc/sw-cp-server/conf.d/trusted_ips.inc: No such file or directory)
stack traceback:
coroutine 0:
        [C]: in function 'lines'
        access_by_lua(plesk_site_preview.conf:15):2: in function <access_by_lua(plesk_site_preview.conf:15):1>, client: 127.0.0.1, server: plesk-site-preview.local, request: "GET /plesk-site-preview/example.com/213.21.0.10/ HTTP/1.0", host: "plesk-site-preview.local"

Cause

Misconfiguration in /etc/sw-cp-server/conf.d/plesk_site_preview.conf config file.

Resolution

1. Backup the original config file:
   

   # mv /etc/sw-cp-server/conf.d/plesk_site_preview.conf{,.bak}

2. Download the attached file to /etc/sw-cp-server/conf.d/ directory.
3. Restart sw-cp-server service:
   

   # service sw-cp-server restart