1drush @none dl registry_rebuild-7.x See https://www.drupal.org/project/registry_rebuild or https://www.deeson.co.uk/labs/drush-registry-rebuild

Empty the files directory. Replace the settings.php file with a copy of the default.settings.php file. Add write permissions to the settings.php file. Drop all tables in the database. Reinstall the site on http://yoursite.com/core/install.php. Ref http://dribbit.eu/drupal-8/reinstall-drupal-8

NOTE: Noticed some memory issue during installation on a VM with 2GB RAM, so if it happens to you, just augment with swap file. 1cd /var/www/sites 2composer create-project drupal-composer/drupal-project:8.x yoursite.example.com --stability dev --no-interaction 3../vendor/bin/drush site-install --site-name="Drupal …

NOTE: Per https://www.drupal.org/project/drupal/releases/8.4.0, drupal8.4.x needs drush 8.1.12+ Method works but has theme issue. Better to use composer method instead. cd /var/www/sites/yourdrupal.com/ drush dl drupal-8 mv drupal-8.4.5 docroot composer install composer update composer require drush/drush drush si …

From Web Browser: generate 'drush uli' Go to /admin/reports/dblog From CLI: 1drush watchdog-show See https://drupal.stackexchange.com/questions/48645/how-to-show-admin-reports-dblog-in-terminal-cli

From drupal admin UI: Administration > Configuration > Development > Performance But will work only if you have drupal admin login. Otherwise, you need to install drush instead and do the 'drush cc all' from there. Some other options -> …

Changing group ownership of the files in "sites/default/files". More details in https://www.drupal.org/docs/7/install/setting-up-the-files-directory

1icasimpan@am2018:~$ sudo mysql_secure_installation 23Securing the MySQL server deployment. 45Connecting to MySQL using a blank password. 67VALIDATE PASSWORD PLUGIN can be used to test passwords 8and improve security. It checks the strength of password 9and allows the users to set only those passwords which are …

Caused by difference in database versions where the latest version you're running does not support 'utf8mb4unicode520_ci'. Search and replace it from within the dump file with 'utf8mb4_unicode_ci'. See details in …

Check /etc/mysql/my.cnf and examine "datadir" value. If it isn't valid or you know the disk is bad, change it. Restart service and all will be well.