I have a view named News containing Aggregated RSS feeds. I noticed duplicate articles were appearing. First I tried to enable Query Settings > DISTINCT, but the duplicates still remained so I disabled DISTINCT. I enabled Use aggregation > YES and added "COUNT(DISTINCT Aggregator feed item: Title) (= 1)" to Filter which seems to do the trick in the preview, however when I try to save the page it results in an error.
The website encountered an unexpected error. Please try again later.
InvalidArgumentException: The configuration property display.default.display_options.filters.title.value.value doesn't exist. in
Drupal\Core\Config\Schema\ArrayElement->get()(line 74 of core\lib\Drupal\Core\Config\Schema\ArrayElement.php).
Is this something I did wrong, or just a bug in Drupal? How should I proceed?