Following is the sample of error I find in Error log
[07-Jan-2019 15:53:00 UTC] PHP Warning: preg_match(): Compilation failed: invalid range in character class at offset 4 in /home/indcara8/public_html/wp-content/plugins/wpmu-dev-seo/includes/external/simple_html_dom.php on line 1364
[07-Jan-2019 16:06:26 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/indcara8/public_html/wp-content/plugins/wpmu-dev-seo/includes/external/simple_html_dom.php on line 691
[07-Jan-2019 03:41:40 UTC] WordPress database error Deadlock found when trying to get lock; try restarting transaction for query DELETE FROM `ua5_options` WHERE `option_name` = '_site_transient_wdp_un_local_projects' made by do_action('admin_init':wink:, WP_Hook->do_action, WP_Hook->apply_filters, WPMUDEV_Dashboard_Site->compatibility_warnings, WPMUDEV_Dashboard_Site->is_upfront_theme_installed, WPMUDEV_Dashboard_Site->get_cached_projects, WPMUDEV_Dashboard_Site->get_transient, get_site_transient, delete_site_option, delete_network_option, delete_option
Disabled the WPMUDEV dashboard plugin for now. Not sure if that is the reason. Please provide solutions to each of the above errors.