Something is going problem with post grid pro plugin. Only post grid is going well.
Please fix that so soon as possible because I have a client to build..
Fatal error: Uncaught Error: Class 'class_post_grid_meta_box' not found in /home/weballa9/public_html/demo/merav/wp-content/plugins/post-grid-pro/includes/functions/functions-post-grid-meta-box.php:102 Stack trace: #0 /home/weballa9/public_html/demo/merav/wp-includes/class-wp-hook.php(287): post_grid_pro_settings_tabs_content_query_post(Array, 704) #1 /home/weballa9/public_html/demo/merav/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(NULL, Array) #2 /home/weballa9/public_html/demo/merav/wp-includes/plugin.php(478): WP_Hook->do_action(Array) #3 /home/weballa9/public_html/demo/merav/wp-content/plugins/post-grid/includes/classes/class-meta-boxes.php(387): do_action('post_grid_metab...', Array, 704) #4 /home/weballa9/public_html/demo/merav/wp-admin/includes/template.php(1345): post_grid_meta_boxs->post_grid_display(Object(WP_Post), Array) #5 /home/weballa9/public_html/demo/merav/wp-admin/edit-form-advanced.php(677): do_meta_boxes(Object(WP_Screen), 'normal', Object(WP_Post)) #6 /home/weballa9/public_html/demo/mer in /home/weballa9/public_html/demo/merav/wp-content/plugins/post-grid-pro/includes/functions/functions-post-grid-meta-box.php on line 102
Greetings from PickPlugins
Could you please update free version first and then try to install pro version.
Hope you checked this documentation to install pro version
https://pickplugins.com/documentation/post-grid/faq/install-pro-version/