When source language is updated, section suggestions are being refetched. However, section suggestion fetching, needs appendix section titles in (updated) source language to be available. When these appendix section titles are not available an uncaught error is being thrown.
Steps to reproduce on https://sx.wmflabs.org:
- Inside dashboard screen click "New translation" button to navigate to "Search for article" screen.
- Select a new source language that has not been used as a source/target language before for this session.
Expected results: Uncaught error is being thrown