Unable to restore a backup when logged in under a customer account: Nothing happens after clicking OK

Applicable to:

#PPP-35576 "The “Define IP Addresses Mapping” screen no longer appears during restoration of the domain which IP address does not match that configured for outgoing mail."
Fixed in:
- Plesk Onyx 17.9 Preview 5 28 August 2018
#PPPM-8094 "The screen &#39Define IP Addresses Mapping&#39 is appeared during restoration of the domain whose IPs do not match with IPs from outgoing mail (as PPP-35576)"<br />Fixed in: <ul><li><a href="https://docs.plesk.com/release-notes/onyx/change-log/#contents-179-preview5">Plesk Onyx 17.9 Preview 5</a> 28 August 2018</li><li><a href="https://docs.plesk.com/release-notes/obsidian/change-log/#contents-18-rc10">Plesk Obsidian Release Candidate 1.0</a> 04 June 2019</li> </ul> </li> </ul> <div class="bug_consider">Please consider updating your server: <ul><li><a href="https://support.plesk.com/hc/en-us/articles/213411749">Plesk Upgrade Guide</a></li> </ul> </div> </div>

It is not possible to restore a full subscription backup when logged in under a customer account. After selecting a backup and clicking the Restore button, a window with IP address mapping settings appears:
- when clicking Save Current IP Mapping to File, the following error message appears:
  
  PLESK_WARN: Permission denied
- when clicking OK, nothing happens.
Several IP addresses are defined at Tools & Settings > IP Addresses.
When logged in under Plesk administrator, the same backup restores successfully.

This is a Plesk bug with ID PPPM-8094, which will be fixed in future product updates.

As workaround, perform the following:

Connect to the Plesk server via SSH.
Create a backup of the original /usr/local/psa/admin/plib/backup/Conflicts/Detector.php file:

# mv /usr/local/psa/admin/plib/backup/Conflicts/Detector.php /usr/local/psa/admin/plib/backup/Conflicts/Detector.php_back
Download the patched file, unpack it and put instead of the original file using these commands:

# wget https://support.plesk.com/hc/article_attachments/360009985953/Detector-PP-17.5-2018.08.03.zip
# unzip ./Detector-PP-17.5-2018.08.03.zip
# mv ./Detector.php /usr/local/psa/admin/plib/backup/Conflicts/Detector.php
Set the correct ownership and permissions for the patched file:

# chown root:root /usr/local/psa/admin/plib/backup/Conflicts/Detector.php
# chmod 644 /usr/local/psa/admin/plib/backup/Conflicts/Detector.php