404 error page

I get this error on all pages accept on first page

https://demo-page.tk/testimonials

this is my code

<?php
		$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;

		query_posts( array('post_type' => 'testimonials','paged' => $paged) );
			if (have_posts()) : while (have_posts()) : the_post(); ?>
			<?php remove_filter ('the_content', 'wpautop'); ?>

			<li><span><?php the_content(); ?><br />-<?php the_title(); ?></span></li>

		<?php endwhile; endif; ?>	

		<?php if(function_exists('wp_paginate')) {
			wp_paginate();
		} ?>

https://www.ads-software.com/plugins/wp-paginate/