@ezar have you installed the latest tvheadend42 from the add-ons folder (see "addons" link at bottom of first post in this thread).
Texture Cache Maintenance Utility: Preload your texture cache for optimal UI performance. Remotely manage media libraries. Purge unused artwork to free up space. Find missing media. Configurable QA check to highlight metadata issues. Aid in diagnosis of library and cache related problems.