Error problems and then upgrade from 1.5.3.1 to 1.5.6.1

Hello,

I suddenly had a problem with my ecommerce, I can't login anymore and then there are two errors:

Fatal error: Call to a member function get() on a non-object in /home/saporiti/public_html/admin/index.php on line 82

Fatal error: Call to a member function get() on a non-object in /home/saporiti/public_html/index.php on line 103

I'd like also to upgrade the website upgrade from the opencart version 1.5.3.1 to 1.5.6.1.

Can someone work on it as soon as possible?

Contact me and I will tell the link and all the informations. Tell me your requests for this work.

After that I have also other works for the website.

Thanks!