Group hierarchy structure displayed incorrectly if labels are missing in a given language

[joelit]

URL address of the page where you encountered the problem

https://finto.fi/mts/en/

Description of the problem

• The upper level of MTS group hierarchy should be 'RDA-terms' & 'Other terms'
• You can verify this by visiting https://finto.fi/mts/fi/
  • Open 'RDA-käsitteet' - it contains nine sub-groups
    • Open 'Toimija' in the hierarchy
      • It contains three sub-groups, with 'Yhteisö'/'Corporate body' being one of them
• Visit https://finto.fi/mts/en/
  • The upper level of MTS group hierarchy contains ten groups
  • The upper level is missing equivalents to 'RDA-terms' & 'Other terms'
  • The upper level contains 'Corporate body'
    • It should be a sub-group of a sub-group for the upper level

Additional information (e.g. screenshots) about the problem

• The culprit seems to be the missing en-prefLabels
• This was tested with Skosmos 3.0 and Skosmos 2.18
• skosmos:fallbackLanguages ( "fi" "sv" ) configuration option was used, but it did not change the behavior

Skosmos 2.18

• Working example of the group structure in Finnish

• Broken example of the group structure in English

Skosmos 3.0-beta1

• Working example of the group structure in Finnish

• Broken example of the group structure in English

The browser you used when the problem appeared

Chrome, though not really applicable