We have a site that we migrated from Drupal 6 to Drupal 8. If we try to update (Just edit and save) one of the terms that were migrated over, we get an error "The value you selected is not a valid choice.". If we add a new term we get no errors.
I tracked it down to the langcode field but not sure how to fix. This is somehow added automatically in Drupal. One thing that I did notice is that in the
taxonomy_term_data table, the langcode was blank for the ones that were migrated but the new ones have
en. I updated all to
en but the problem remains.