Hello,
Please help me fix my site.
My site is blank.
If I deactivate Elementor page builder, the site works fine.
What can I do to continue using Elementor.
When I deactivated other plugins the error did not stop.
Below are error messages from Query Monitor:

Fatal error: Uncaught Error: Call to a member function get_main_post() on boolean
in /home/xtfgpvt345retw/public_html/wp-content/plugins/elementor/core/kits/manager.php on line 171
Call stack:
1. Elementor\C\K\Manager::get_kit_for_frontend()
wp-content/plugins/elementor/core/kits/manager.php:258
2. Elementor\C\K\Manager::add_body_class()
wp-content/plugins/elementor/core/kits/manager.php:282
3. Elementor\C\K\Manager::Elementor\C\K\{closure}()
wp-includes/class-wp-hook.php:287
4. WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:311
5. WP_Hook::do_action()
wp-includes/plugin.php:478
6. do_action()
wp-includes/general-template.php:3009
7. wp_head()
wp-content/themes/generatepress/header.php:17
8. require_once()
wp-includes/template.php:730
9. load_template()
wp-includes/template.php:676
10. locate_template()
wp-includes/general-template.php:48
11. get_header()
wp-content/themes/generatepress/404.php:12
12. include()
wp-includes/template-loader.php:106
13. require_once()
wp-blog-header.php:19
14. require()
index.php:17
Thanks.