Unknown table ‘wp_posts’ in group statement

I am getting a new error:

WordPress database error: [Unknown table ‘wp_posts’ in group statement]
SELECT ID, post_title FROM wp_posts p LEFT JOIN wp_term_relationships tr ON p.ID = tr.object_id LEFT JOIN wp_term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id LEFT JOIN wp_ak_popularity pop ON p.ID = pop.post_id WHERE tt.term_id = '467' AND tt.taxonomy = 'category' AND post_status = 'publish' AND post_type = 'post' AND post_date < NOW() GROUP BY wp_posts.ID ORDER BY pop.total DESC LIMIT 10

This happens only on the categories pages:Example

Other requests work fine: Example

wp_posts does exist…

Here is the php code from the widget:

<?php /* If this is a 404 page */ if (is_404()) { ?>
			<?php /* If this is a category archive */ } elseif (is_category()) { ?>
			<p>You are currently browsing the archives for the <?php single_cat_title(''); ?> category.</p>

			<li><h2>Most Popular in '<?php single_cat_title(''); ?>'</h2>
				<ul>
				<?php akpc_most_popular_in_cat(); ?>
				</ul>
			</li>

			<?php /* If this is a yearly archive */ } elseif (is_day()) { ?>
			<p>You are currently browsing the <a href="<?php echo get_settings('siteurl'); ?>"><?php echo bloginfo('name'); ?></a> weblog archives
			for the day <?php the_time('l, F jS, Y'); ?>.</p>

			<?php /* If this is a monthly archive */ } elseif (is_month()) { ?>
			<p>You are currently browsing the <a href="<?php echo get_settings('siteurl'); ?>"><?php echo bloginfo('name'); ?></a> weblog archives
			for <?php the_time('F, Y'); ?>.</p>

			<li><h2>Most Popular in <?php the_time('F, Y'); ?></h2>
				<ul>
				<?php akpc_most_popular_in_month(); ?>
				</ul>
			</li>

      <?php /* If this is a yearly archive */ } elseif (is_year()) { ?>
			<p>You are currently browsing the <a href="<?php echo get_settings('siteurl'); ?>"><?php echo bloginfo('name'); ?></a> weblog archives
			for the year <?php the_time('Y'); ?>.</p>

		 <?php /* If this is a monthly archive */ } elseif (is_search()) { ?>
			<p>You have searched the <a href="<?php echo get_settings('siteurl'); ?>"><?php echo bloginfo('name'); ?></a> weblog archives
			for <strong>'<?php echo wp_specialchars($s); ?>'</strong>. If you are unable to find anything in these search results, you can try one of these links.</p>

			<?php /* If this is a monthly archive */ } elseif (isset($_GET['paged']) && !empty($_GET['paged'])) { ?>
			<p>You are currently browsing the <a href="<?php echo get_settings('siteurl'); ?>"><?php echo bloginfo('name'); ?></a> weblog archives.</p>

			<?php } ?>

			<?php if (!is_archive() && !is_category()) { ?>
			<li><h2>Most Popular Posts</h2>
				<ul>
				<?php akpc_most_popular(); ?>
				</ul>
			</li>
			<?php } ?>