package mysql-server-5.7 5.7.20-0ubuntu0.16.04.1 failed to upgrade: subprocess installed post-installation script returned error exit status 1

[Serg Programmer]

I have upgraded packages/apps in "Update Apps" app (Обновление приложений)

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mysql-server-5.7 5.7.20-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-97.120-generic 4.4.87
Uname: Linux 4.4.0-97-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
Date: Tue Oct 24 18:58:43 2017
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-xenial-amd64-20160624-2
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2017-02-18 (248 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
Logs.var.log.daemon.log:

MySQLConf.etc.mysql.conf.d.mysql.cnf: [mysql]
MySQLConf.etc.mysql.conf.d.mysqldump.cnf:
 [mysqldump]
 quick
 quote-names
 max_allowed_packet = 16M
MySQLConf.etc.mysql.mysql.conf.d.mysqld_safe_syslog.cnf:
 [mysqld_safe]
 syslog
MySQLVarLibDirListing: ['mysql', 'performance_schema', 'auto.cnf', 'sys', 'ibdata1', 'ib_logfile0', 'debian-5.7.flag', 'ib_buffer_pool', 'ib_logfile1', 'mysql_upgrade_info']
ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-97-generic.efi.signed root=UUID=be504170-c332-4d45-9258-33545039adde ro quiet splash vt.handoff=7
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.2
 apt 1.2.24
SourcePackage: mysql-5.7
Title: package mysql-server-5.7 5.7.20-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)
upstart.mysql.override: manual

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #1726656, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.