@stefan-korn I'm not sure about this -- can you give an example case where $dist->{$matches[2]} would be unset?

@dafeder : Have you read the description in #4179 ? I cannot reproduce this on plain DKANv2, only with our customized schema. But it should not return an empty array as value there, this is wrong in my opinion.

@stefan-korn I did read it, I'd like to observe the behavior before and after the fix to properly review. Can you post an example schema that would let me reproduce the issue?

@dafeder : I am attaching an example of dataset.json which can produce the issue. There is new property "dctconformsto" in the distribution (as an array of objects).
The steps to reproduce the issue are:

• add a dataset with a distribution that has this property filled (once or more).
• add the property to the search index DKAN.
• Reindex the search index
• indexing will fail with Error: Object of class stdClass could not be converted to string in Drupal\search_api\Plugin\search_api\data_type\StringDataType->getValue() (line 23 of /var/www/plain-dkan/docroot/modules/contrib/search_api/src/Plugin/search_api/data_type/StringDataType.php).

dataset.json