I have a problem upgrading mysql-server-5.7 (5.7.23-0ubuntu0.16.04.1), Plesk version is 17.8.11 Update #15, this is the content of file "parallels-installation-log.txt:
[2018-08-01 13:46:24.492251] Installation started in background
[2018-08-01 13:46:24.492343]
Getting bootstrapper packages to...