If a4kSubtitles fails, you can manually trigger searches using other add-ons that support searching rather than just ID-based.
A4kSubtitles works by searching subtitle websites (like OpenSubtitles.org or Podnapisi.net) using a unique identifier for the video. The most reliable identifier is the (e.g., tt0111161 for The Shawshank Redemption ). a4ksubtitles imdb id not provided