The following issues have been resolved:

[-] Plesk Updates are not installed automatically if debug option was enabled in panel.ini (PPPM-1667)
[-] Mail notifications about resource overuse did not show a list of overused resources. (PPPM-869)
[-] (Windows) Older database backups were transferred to the destination server instead of the actual database. ( PPPM-1593)
[-] (Windows) Mail content was not migrated from Plesk and SmarterMail 7.6.
[-] (Windows) SMTP traffic was incorrectly calculated on installations with SmarterMail. (PPPM-1624)
[-] (Windows) Upgrade from older Plesk fails if mysql option innodb_log_file_size was changed in my.cnf for admin MySQL server. (PPPM-1646)
[-] (Linux) The repair utility failed to restore vhost permissions when it was executed with the –restore-vhosts-permissions option (/usr/local/psa/bin/repair –restore-vhosts-permissions). (PPPM-1399)
[-] (Linux) Watchdog 2.03 could not start after a server was restarted. (PPPM-1311)
[-] (Linux) A number of files were missing in Update 26 for CloudLinux 5/6 x32/x64.