I recently set my site live, and I was attempting to setup the sitemap.xml file, unfortunately it generates the (what seems common) and vague error "We can't generate the sitemap right now."
A little info first: Magento CE 2.1.3, php 7.0.16, nginx hosted service.
However, when I look into my log files, this error is generated in the system.log file:
[2017-03-10 20:38:13] main.CRITICAL: Exception message: SQLSTATE[42S22]: Column not found: 1054 Unknown column 't2_name.value' in 'field list', query was: SELECT `e`.`entity_id`, `e`.`entity_id`, `e`.`updated_at`, `url_rewrite`.`request_path` AS `url`, IFNULL(t2_name.value, t1_name.value) AS `name`, IFNULL(t2_thumbnail.value, t1_thumbnail.value) AS `thumbnail` FROM `catalog_product_entity` AS `e`
INNER JOIN `catalog_product_website` AS `w` ON e.entity_id = w.product_id
LEFT JOIN `url_rewrite` ON e.entity_id = url_rewrite.entity_id AND url_rewrite.is_autogenerated = 1 AND url_rewrite.metadata IS NULL AND url_rewrite.store_id = '31' AND url_rewrite.entity_type = 'product'
LEFT JOIN `catalog_product_entity_int` AS `t1_visibility` ON e.entity_id = t1_visibility.entity_id AND t1_visibility.store_id = 0 AND t1_visibility.attribute_id = '99'
LEFT JOIN `catalog_product_entity_int` AS `t2_visibility` ON t1_visibility.entity_id = t2_visibility.entity_id AND t1_visibility.attribute_id = t2_visibility.attribute_id AND t2_visibility.store_id = '31'
LEFT JOIN `catalog_product_entity_int` AS `t1_status` ON e.entity_id = t1_status.entity_id AND t1_status.store_id = 0 AND t1_status.attribute_id = '97'
LEFT JOIN `catalog_product_entity_int` AS `t2_status` ON t1_status.entity_id = t2_status.entity_id AND t1_status.attribute_id = t2_status.attribute_id AND t2_status.store_id = '31'
LEFT JOIN `catalog_product_entity_varchar` AS `t1_name` ON e.entity_id = t1_name.entity_id AND t1_name.store_id = 0 AND t1_name.attribute_id = '73'
LEFT JOIN `catalog_product_entity_varchar` AS `t1_thumbnail` ON e.entity_id = t1_thumbnail.entity_id AND t1_thumbnail.store_id = 0 AND t1_thumbnail.attribute_id = '89' WHERE (w.website_id = '1') AND ((IF(t2_visibility.value_id > 0, t2_visibility.value, t1_visibility.value)) IN(3, 2, 4)) AND ((IF(t2_status.value_id > 0, t2_status.value, t1_status.value)) IN(1))
Trace: #0 /home/userhome/public_html/vendor/magento/framework/DB/Statement/Pdo/Mysql.php(95): Zend_Db_Statement_Pdo->_execute(Array)
#1 /home/userhome/public_html/vendor/magento/zendframework1/library/Zend/Db/Statement.php(303): Magento\Framework\DB\Statement\Pdo\Mysql->_execute(Array)
#2 /home/userhome/public_html/vendor/magento/zendframework1/library/Zend/Db/Adapter/Abstract.php(480): Zend_Db_Statement->execute(Array)
#3 /home/userhome/public_html/vendor/magento/zendframework1/library/Zend/Db/Adapter/Pdo/Abstract.php(238): Zend_Db_Adapter_Abstract->query('SELECT `e`.`ent...', Array)
#4 /home/userhome/public_html/vendor/magento/framework/DB/Adapter/Pdo/Mysql.php(465): Zend_Db_Adapter_Pdo_Abstract->query('SELECT `e`.`ent...', Array)
#5 /home/userhome/public_html/vendor/magento/framework/DB/Adapter/Pdo/Mysql.php(520): Magento\Framework\DB\Adapter\Pdo\Mysql->_query('SELECT `e`.`ent...', Array)
#6 /home/userhome/public_html/vendor/magento/module-sitemap/Model/ResourceModel/Catalog/Product.php(289): Magento\Framework\DB\Adapter\Pdo\Mysql->query(Object(Magento\Framework\DB\Select))
#7 /home/userhome/public_html/vendor/magento/module-sitemap/Model/Sitemap.php(245): Magento\Sitemap\Model\ResourceModel\Catalog\Product->getCollection('31')
#8 /home/userhome/public_html/vendor/magento/module-sitemap/Model/Sitemap.php(338): Magento\Sitemap\Model\Sitemap->_initSitemapItems()
#9 /home/userhome/public_html/vendor/magento/module-sitemap/Controller/Adminhtml/Sitemap/Generate.php(27): Magento\Sitemap\Model\Sitemap->generateXml()
#10 /home/userhome/public_html/vendor/magento/framework/App/Action/Action.php(102): Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate->execute()
#11 /home/userhome/public_html/vendor/magento/module-backend/App/AbstractAction.php(226): Magento\Framework\App\Action\Action->dispatch(Object(Magento\Framework\App\Request\Http))
#12 /home/userhome/public_html/vendor/magento/framework/Interception/Interceptor.php(74): Magento\Backend\App\AbstractAction->dispatch(Object(Magento\Framework\App\Request\Http))
#13 /home/userhome/public_html/vendor/magento/framework/Interception/Chain/Chain.php(70): Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate\Interceptor->___callParent('dispatch', Array)
#14 /home/userhome/public_html/vendor/magento/framework/Interception/Chain/Chain.php(63): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Sitemap...', 'dispatch', Object(Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate\Interceptor), Array, 'adminAuthentica...')
#15 /home/userhome/public_html/vendor/magento/module-backend/App/Action/Plugin/Authentication.php(143): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain\{closure}(Object(Magento\Framework\App\Request\Http))
#16 /home/userhome/public_html/vendor/magento/framework/Interception/Chain/Chain.php(67): Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(Object(Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#17 /home/userhome/public_html/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Sitemap...', 'dispatch', Object(Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate\Interceptor), Array, 'adminMassaction...')
#18 /home/userhome/public_html/vendor/magento/module-backend/App/Action/Plugin/MassactionKey.php(33): Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#19 /home/userhome/public_html/vendor/magento/framework/Interception/Interceptor.php(142): Magento\Backend\App\Action\Plugin\MassactionKey->aroundDispatch(Object(Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#20 /home/userhome/public_html/var/generation/Magento/Sitemap/Controller/Adminhtml/Sitemap/Generate/Interceptor.php(26): Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate\Interceptor->___callPlugins('dispatch', Array, Array)
#21 /home/userhome/public_html/vendor/magento/framework/App/FrontController.php(55): Magento\Sitemap\Controller\Adminhtml\Sitemap\Generate\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#22 /home/userhome/public_html/vendor/magento/framework/Interception/Interceptor.php(74): Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
#23 /home/userhome/public_html/vendor/magento/framework/Interception/Chain/Chain.php(70): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
#24 /home/userhome/public_html/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'install')
#25 /home/userhome/public_html/vendor/magento/framework/Module/Plugin/DbStatusValidator.php(69): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#26 /home/userhome/public_html/vendor/magento/framework/Interception/Interceptor.php(142): Magento\Framework\Module\Plugin\DbStatusValidator->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#27 /home/userhome/public_html/var/generation/Magento/Framework/App/FrontController/Interceptor.php(26): Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', Array, Array)
#28 /home/userhome/public_html/vendor/magento/framework/App/Http.php(135): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#29 /home/userhome/public_html/vendor/magento/framework/App/Bootstrap.php(258): Magento\Framework\App\Http->launch()
#30 /home/userhome/public_html/pub/index.php(37): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))
#31 {main} [] []