When migrating all backslashes were stripped and special signs are converted in html entities

You can probably remove HTML entity filtering on import, using:

add_filter( 'force_filtered_html_on_import' , '__return_false' );

as answered here.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)