Reply To: Unknown character set error when importing from vBulletin 4.2.1
Any chance you could talk to your webhost and have the MySQL version updated?
WordPress’ minimum requirements per https://wordpress.org/about/requirements/ are WordPress also works with PHP 5.2.4+ and MySQL 5.0+ which you are using but I suspect the phpMyAdmin warning Your PHP MySQL library version 5.1.49 differs from your MySQL server version 5.0.51a. you see are probably related to this issue.
If your vBulletin database uses utf8_mb4 but your WordPress install is only using utf8 then you’ll run into issues. As Pascal pointed out with that link, you are using MySQL v5.0.x which doesn’t support utf8_mb4, only MySQL v5.5.3 and above does.
If the vBulletin database used utf8 rather than utf8mb4 then I’d expect the import to work just fine, but because of the different character sets and collation differences the only way around this I see is to resolve this by upgrading to at least MySQL v5.5.3.
