I enabled entity translation and related modules using drush (site already has lot of content).
drush en -y entity_translation admin_language pathauto_i18n title languageicons entity_translation_i18n_menu i18n_block i18n_field
Then i enabled the feature with translated content type. After that i get the following error when i navigate to /admin/structure/types/manage/article.
EntityMetadataWrapperException: Unknown data property commerce_line_items. in EntityStructureWrapper->getPropertyInf()(line 335 of /drupal_root/sites/all/modules/entity/includes/entity.wrapper.inc)
When i checked the status page(/admin/reports/status) i saw the following waning in tokens section
$info['types']['node'] $info['types']['term'] $info['types']['vocabulary'] $info['types']['file'] $info['types']['user'] $info['types']['current-user']
Also, the fields in Search API index (/admin/config/search/search_api/index/solr_index_test/fields) dont include node title, body etc.
I solved the same error in another instance by running update.php(i had Panels update pending). There was no pending database updates in the current situation.
Solution was simple – run drush eval on any module updates in my case panels as follows
drush eval "panels_update_7306"
That solved my headache for the last four hours!