Error due to code in Form Vaildation.php

We need more information then just that.

What error are you getting?

Show the code that is generating the error.

This was my original error:

Fatal error: Call to a member function num_rows() on a non-object in /home4/cultured/public_html/system/libraries/Form_validation.php on line 1122

I thought it was because I didnt have a form vaidation in my library folder. After making one it messed up my login so I took it out. Now I still get this error after trying to test register. How do I fix this? I thought I added the proper links within my autoload and config files, I guess I missing something else. Thank you for the help