Migration check in plesk shows this error:

The ‘max_allowed_packet’ parameter on the source database server is 16777216, which is bigger than on the destination server, where it is 1048576

RDP the the server. The file is at C:Program Files (x86)ParallelsPleskDatabasesMySQLDatamy.ini

Add this to it:

[mysqld]
# max_allowed_packet=16M