In the last step of the installer it complains the following error described below
Check config file
defaults.inc.php: OK
config.inc.php: OK
Check if directories are writable
QuoteRoundcube may need to write/save files into these directories
C:\inetpub\wwwroot/temp/: OK
C:\inetpub\wwwroot/logs/: OK
Check DB config
DSN (write): NOT OK(SQLSTATE[HY000] [2054] Server sent charset unknown to the client. Please, report to the developers)
Make sure that the configured database exists and that the user has write privileges
The database, user and password properly configured
My server
Windows Server 2008 R2
IIS 7.5 with PHP 5.6
MySQL Server Community 8
With MySQL 5.7 the installation occurred without problems
Every help is welcome