Migrate all content from source site to target site.
Source site, WordPress 3.9.1, Mysql 5.5.45.
Target site, WordPress 5.2.3, Mysql 8.0.17.
Source site send a backup to target site, and target site receive a backup from source site.
First, transfer Database, plugins, theme, uploads, other, to target site; Restore the backup on target site with checked box of migration and replace.
But it failed, when I visited the target site, it said “… technical difficult”, not any more details.
Second, transfer Database, plugins, theme, uploads, other + wordpress core without wp-config.php file, to target site; Restore the backup on target site with checked box of migration and replace.
But it also failed, and I can’t visit the target site, 500 error.
So, please give me some help.