SQLSTATE[42S02]: Base table or view not found: 1146 Table 'db.design_config_grid_flat' doesn't exist
Table is missing. Run in sql console below sql query. After run sql query run php bin/magento indexer:reindex
CREATE TABLE `design_config_grid_flat` (
`entity_id` int(10) unsigned NOT NULL COMMENT 'Entity ID',
`store_website_id` int(11) DEFAULT NULL COMMENT 'Store_website_id',
`store_group_id` int(11) DEFAULT NULL COMMENT 'Store_group_id',
`store_id` int(11) DEFAULT NULL COMMENT 'Store_id',
`theme_theme_id` varchar(255) DEFAULT NULL COMMENT 'Theme_theme_id',
PRIMARY KEY (`entity_id`),
KEY `DESIGN_CONFIG_GRID_FLAT_STORE_WEBSITE_ID` (`store_website_id`),
KEY `DESIGN_CONFIG_GRID_FLAT_STORE_GROUP_ID` (`store_group_id`),
KEY `DESIGN_CONFIG_GRID_FLAT_STORE_ID` (`store_id`),
FULLTEXT KEY `DESIGN_CONFIG_GRID_FLAT_THEME_THEME_ID` (`theme_theme_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='design_config_grid_flat';