Install Plesk Panel 8.6, 9.5.5, 10.x, 11.x updates manually
Sometime the Plesk fails to update automatically, the following commands can be used to update Plesk manually.
For Linux:
/usr/local/psa/admin/sbin/autoinstaller --select-product-id plesk --select-release-current --reinstall-patch --install-component base
For Windows:
%plesk_dir%adminbin>ai.exe --select-product-id panel --select-release-current --reinstall-patch --install-component base