Warning: require_once(/var/www/html/includes/database/mysqli/database.inc): Failed to open stream: No such file or directory in /var/www/html/includes/database/database.inc on line 1795

Fatal error: Uncaught Error: Failed opening required '/var/www/html/includes/database/mysqli/database.inc' (include_path='.:/usr/local/lib/php') in /var/www/html/includes/database/database.inc:1795
Stack trace:
#0 /var/www/html/includes/database/database.inc(1582): Database::openConnection('default', 'default')
#1 /var/www/html/includes/database/database.inc(2687): Database::getConnection()
#2 /var/www/html/includes/cache.inc(359): db_escape_table('cache_bootstrap')
#3 /var/www/html/includes/cache.inc(340): DrupalDatabaseCache->getMultiple(Array)
#4 /var/www/html/includes/cache.inc(57): DrupalDatabaseCache->get('module_implemen...')
#5 /var/www/html/includes/module.inc(763): cache_get('module_implemen...', 'cache_bootstrap')
#6 /var/www/html/includes/module.inc(963): module_implements('watchdog')
#7 /var/www/html/includes/bootstrap.inc(2081): module_invoke_all('watchdog', Array)
#8 /var/www/html/includes/errors.inc(208): watchdog('php', '%type: !message...', Array, 4)
#9 /var/www/html/includes/errors.inc(64): _drupal_log_error(Array, false)
#10 /var/www/html/includes/bootstrap.inc(2672): _drupal_error_handler_real(2, 'require_once(/v...', '/var/www/html/i...', 1795)
#11 /var/www/html/includes/database/database.inc(1795): _drupal_error_handler(2, 'require_once(/v...', '/var/www/html/i...', 1795)
#12 /var/www/html/includes/database/database.inc(1795): require_once('/var/www/html/i...')
#13 /var/www/html/includes/database/database.inc(1582): Database::openConnection('default', 'default')
#14 /var/www/html/includes/database/database.inc(2687): Database::getConnection()
#15 /var/www/html/includes/cache.inc(359): db_escape_table('cache_bootstrap')
#16 /var/www/html/includes/cache.inc(340): DrupalDatabaseCache->getMultiple(Array)
#17 /var/www/html/includes/cache.inc(57): DrupalDatabaseCache->get('module_implemen...')
#18 /var/www/html/includes/module.inc(763): cache_get('module_implemen...', 'cache_bootstrap')
#19 /var/www/html/includes/module.inc(963): module_implements('system_theme_in...')
#20 /var/www/html/modules/system/system.module(2531): module_invoke_all('system_theme_in...')
#21 /var/www/html/includes/theme.inc(798): _system_rebuild_theme_data()
#22 /var/www/html/includes/theme.maintenance.inc(57): list_themes()
#23 /var/www/html/includes/bootstrap.inc(2965): _drupal_maintenance_theme()
#24 /var/www/html/includes/errors.inc(177): drupal_maintenance_theme()
#25 /var/www/html/includes/bootstrap.inc(2690): _drupal_log_error(Array, true)
#26 [internal function]: _drupal_exception_handler(Object(Error))
#27 {main}
  thrown in /var/www/html/includes/database/database.inc on line 1795