[thincom2000]

You might have PHP 5.4.29 installed on your server as you say, but apparently your server also has PHP < 5.3 installed, and it is using that instead for vBulletin. You will have to make sure in your Apache, nginx, or other config, that it is using the correct path to the PHP 5.4.29 binary when a .php request comes in.

If you maintain multiple versions of PHP, it is usually easier to keep track of this if the PHP path has the version number in it. But I have found that it is sometimes possible to update the wrong PHP location if you forget to set your prefixes properly when you compile the update.

If this error did not occur, then the loaded page should tell you that the PHP version is too low, and the actual PHP version that is executing the page. You can try to get at least that far, so it can give you some clues about your version, by editing vault/core/model/vw.php. Find:

$classname::select_child($class, $file, $depends);

Replace with:

call_user_func_array(array($classname, 'select_child'), array(&$class, &$file, $depends));