Lots of errors after server move

Hello all!

today we moved our clients' websites to a new server.
2 websites are now covered in errors.

I'm pasting one here but you can check the website here: http://www.naturaviva.gr

Strict Standards: Non-static method GKIS_BlackAndWhite_Image::checkCache() should not be called statically, assuming $this from incompatible context in /home/dcacomgr/public_html/naturaviva.gr/modules/mod_image_show_gk4/styles/gk_black_and_white/class.image.php on line 50

Strict Standards: Non-static method JSite::getMenu() should not be called statically, assuming $this from incompatible context in /home/dcacomgr/public_html/naturaviva.gr/templates/gk_restaurant/lib/framework/helper.layout.php on line 212

Strict Standards: Non-static method NSP_GK4_Utils::cutText() should not be called statically, assuming $this from incompatible context in /home/dcacomgr/public_html/naturaviva.gr/modules/mod_news_pro_gk4/tmpl/layout.parts.php on line 21

Joomla 2.5.16
Template is Restaurant

My provider said that it's because the plugins are outdated and not compatible with newer server's php version.

How do I upgrade the template, Image Show Gk4, Mod News Pro Gk4 and all the plugins mentioned in the errors and not risk ruining the whole thing???

Please help
Thank you in advance

Yes, help please. Would like to know also. I'm using Shop&Buy template 3.9.2. Says a new version "3.10 is available. So how do I upgrade without losing my Quickstart setup. Thanks!

I found the solution!

Inside the index.php in the template folder,

ini_set('display_errors','on'); put "off"

It stops displaying the errors and everything works fine

<?php

/**
*
* Main file
*
* @version 3.0.0
* @package Gavern Framework
* @copyright Copyright (C) 2010 - 2012 GavickPro. All rights reserved.
*
*/

// No direct access.
defined('_JEXEC') or die;
// enable showing errors in PHP
ini_set('error_reporting', E_ALL);
ini_set('display_errors','on');
// include framework classes and files
require_once('lib/gk.framework.php');
// run the framework
$tpl = new GKTemplate($this, $GK_TEMPLATE_MODULE_STYLES);

// EOF

I try put off but it doesn't work. Any other idea? , Why it is happened?

Yes, we have whole new guide for you:
http://www.gavick.com/documentation/gen ... ic-method/