My loop is duplicating, i'm totally stuck please help me out

possibly caused by using the query without the ‘paged’ parameter;

try:

<?php $main_query = new WP_Query('cat=-25&paged='.get_query_var('paged')); ?>

or alternatively:

<?php global $query_string; $main_query = new WP_Query($query_string.'&cat=-25); ?>

https://codex.www.ads-software.com/Function_Reference/query_posts#Usage_Note
https://codex.www.ads-software.com/Class_Reference/WP_Query#Pagination_Parameters
(contrary to the note in the last link, try with ‘paged’, if this does not work, try ‘page’)

Thanks that seems to do the job!

I have read the pages from your links already, tried almost everything and nothign seemed to work.

In addition to my query, i got it from here: https://digwp.com/2011/05/loops/ they obviously say

Notice, however, that with WP_Query, we don’t need the $query_string variable

So their information is incorrect or?

I’m still trying to understand.

Thanks again!