Failed to update Plesk error message after successful updates installation

Symptoms

• The following error message can be found on Plesk Home page:

  PLESK_ERROR: Update failed.
  ...
  2017-11-30 08:40:22 ERROR: [u'Errors were encountered while downloading packages.', u'curl-7.29.0-42.el7_4.1.x86_64: [Errno 256] No more mirrors to try.', u'apr-1.4.8-3.el7_4.1.x86_64: [Errno 256] No more mirrors to try.', u'libcurl-7.29.0-42.el7_4.1.x86_64: [Errno 256] No more mirrors to try.']
  2017-11-30 08:40:22 ERROR: Exited with returncode 1.

• The update itself was installed correctly.
• The update was triggered by pressing Install button on the Home page.

Cause

Plesk bug with ID PPPM-6580,  which will be fixed in next product updates.

Resolution

The message can be safely closed.

As a workaround, in order to avoid this message from re-occurring, install micro-updates via Tools & Settings > Updates and Upgrades or do the following:

1. Connect to server over SSH.

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