Hello,

I have the same issue, probably due to custom post type.
For exemple I have the following error message with The Event Calendar Plugin.
After updating the vc_composer plugin to 4.2 I have created a page with “Block 22” then selected the custom type “tribe_events”.
Everything is ok with the page but when I click the url the open the related post, then I have before the post following error message :

wp booster error:
td_module: td_module_single($post): $post is not WP_Post
/srv/data/web/vhosts/htdocs/wp-content/themes/Newspaper/includes/wp_booster/td_module.php
Home

wp booster error:
td_module: td_module_single($post): $post is not WP_Post
/srv/data/web/vhosts/htdocs/wp-content/themes/Newspaper/includes/wp_booster/td_module.php

Any idea ?

Thanks in advance