Hello,
1/ It is recommended to run import on a fresh WordPress installation. For this you can use WordPress Database Reset plugin https://wordpress.org/plugins/wordpress-database-reset/ The plugin can be used to remove all the existing content and install a new version from scratch.
Also, make sure that all 3rd party plugins are disabled before the import. Demo content can be imported incorrectly in case a lot of 3rd party plugins were activated on the site before the import.
2/ https://prnt.sc/tw-FD61BV3NE – this is no error, but an info message that is shown for all our customers.
Regards