My website won't work!

I can't get the "welcome to altervista" thing to go away on my site. I used the Mysidia Adoptables script and it installed and I can see the Mysidia logo as the tab thumbnail, but nothing else to show that it actually updated. I've tried clearing my cache and everything.

[alemoppo]

On your site there is the error:

Fatal error: require(): Failed opening required '/var/www/html/inc/smarty/Smarty.class.php' (include_path='.:') in /membri/nroomies/classes/class_mysidia.php on line 334

It seems some wrong configuration: you can't access to /var/www... Use relative path.

Bye!

[reim]

On your site there is the error:

It seems some wrong configuration: you can't access to /var/www... Use relative path.

Bye!

I fixed but now I'm getting this error and a failing to open stream error:

Fatal error: require(): Failed opening required 'classes/resource/native/objective.php' (include_path='.:') in /membri/reim/index.php on line 3

[alemoppo]

classes/resource/native/objective.php

Is this file exists in your account?

Bye!