Use a logfile and see where it is stuck. If you are using a recent rbej OpenELEC build there is a bug which can cause JSON to hang when processing TV shows, this should be fixed in the next rbej release (probably).
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.