[FIXED BUG] Failed to update Plesk error message after successful updates installation

Applicable to:

The following error message can be found on Plesk Home page:
PLESK_ERROR: Failed to update Plesk. To close this message, click here.
The update itself was installed correctly according to in /var/log/plesk/install/autoinstaller3.log file:
CONFIG_TEXT: [2018-11-16 11:18:27.789971] Environment locale name is 'C'
[2018-11-16 11:18:27.802342]

Plesk Installer 3.22.11 (revision 7b9797d7a12f) started at (timezone CET) Fri Nov 16 11:18:27 2018
Command line arguments: /usr/local/psa/admin/bin/autoinstaller --select-product-id plesk --select-release-current --upgrade-installed-components
...
[2018-11-16 11:22:30.819394]
The changes were applied successfully.
The update was triggered by pressing Install button on the Home page according to in /var/log/plesk/httpsd_access_log file:
# grep "/admin/update/components" /var/log/plesk/httpsd_access_log
203.0.113.2 - - [16/Nov/2018:11:18:27 +0100] "POST /admin/update/components?_randomId=212246 HTTP/1.1" 302 5 "https://example.com.com:8443/admin/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:62.0) Gecko/20100101 Firefox/62.0" "-"'/admin/update/components' '' '/usr/local/psa/admin/htdocs'

Plesk bug with ID PPPM-6580, which is fixed in Plesk Obsidian.

Please consider updating your server:

Click on a section to expand

Workaround

The message can be safely closed.

To avoid this message from re-occurring, install micro-updates via Tools & Settings > Updates and Upgrades or do the following:

Note: If direct SSH access to the server is not possible, contact server administrator for further assistance.

2. Run the following command to install Plesk updates:

# plesk installer --select-release-current --upgrade-installed-components --reinstall-patch

If the solution above does not help, check resolution part from the article Cannot install system updates via Plesk: [Errno 256] No more mirrors to try