Plugin creating many error.log entires

Hi.
I’ve just noticed my site’s hosting space has been used up. I discovered a 2.3GB error_log file.

Most of the entries look something like this:
[10-Apr-2017 09:33:43 UTC] WordPress database error Unknown column ‘shares_count’ in ‘field list’ for query SELECT shares_count FROM wp_huge_it_share_params LIMIT 1 made by require(‘wp-blog-header.php’), require_once(‘wp-includes/template-loader.php’), include(‘/themes/headway/index.php’), HeadwayDisplay::layout, HeadwayDisplay::grid, HeadwayLayoutRenderer->display, HeadwayGridRenderer->render_grid, HeadwayBlocks::display_block, do_action(‘headway_block_content_content’), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, HeadwayContentBlock->content, HeadwayContentBlockDisplay->display, HeadwayContentBlockDisplay->loop, HeadwayContentBlockDisplay->display_entry, HeadwayContentBlockDisplay->display_entry_content, the_content, apply_filters(‘the_content’), WP_Hook->apply_filters, call_user_func_array, hugeit_share_my_the_content_filter, hugeit_share_buttons, hugeit_share_show_published_share_buttons_1, hugeit_share_front_end_share_buttons, hugeit_share_show_hide_shares_count

This has only been happening since Share Buttons was updated on the site at the end of February (2017). 99.9% of the 2.3GB error log has this sort of error message.

Also found your website has been categorised (by my Firefox browser) as “harmful” – it’s unavailable in Chrome.

What is the problem, and how can it be fixed?

Thanks, David