vBulletin 5.1.5 Installation error.

[SPH0]

I'm trying to install vBulletin 5.1.5 on my website and it's giving me this error:

Fatal error: Call to undefined function mysqli_init() in /home/sph0/public_html/forums/core/vb/database/mysqli.php on line 86


I've done everything right, made the database, set the username and the password, renamed the config.php.new files

Link: http://sph0.com/forums/
PHP Version:5.4.33
Web Server: Apache v2.2.29 (cgi-fcgi)

[Mark.B]

Edit /core/includes/config.php

Find:

$config['Database']['dbtype'] = 'mysqli'; 

Change to:

$config['Database']['dbtype'] = 'mysql'; 

[SPH0]

Edit /core/includes/config.php

Find:

$config['Database']['dbtype'] = 'mysqli'; 

Change to:

$config['Database']['dbtype'] = 'mysql'; 

Okay. I did that but now it gives me another error:
Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 77 bytes) in /home/sph0/public_html/forums/core/vb/database.php on line 255

[SPH0]

By looking at my PHP configuration:
memory_limit = 32M

[Guest]

Set it to 64M as test.