Gefunden im Supportbereich von Akeeba:
Site Restoration - Akeeba Ltd
Akeeba Ltd is a provider of premium software for Joomla! and WordPress
www.akeeba.com
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you have not enabled mysqli or mysqlnd in your PHP. Therefore PHP has no way to connect to a MySQL (or MariaDB, it's the same API) database server.
You need to enable MySQL database support in PHP before trying to restore the site. You can do so enabling either mysqli or mysqlnd support. Please ask your host for instructions on doing that. The exact steps to do that depend on how the server is set up, something you are paying your host to manage for you.
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