Short answer: a failed library update is almost never one problem. Open the update log, see which sources error, and fix by category: rate-limit messages mean update less at once; every title from one source failing means that source is down or has moved; the whole update dying midway usually means Android killed the app in the background (battery optimization).
Read the failure before fixing it
- Only some titles fail — those titles’ source changed something. Open one failing title: if the source itself will not load, the extension needs an update or the series needs migrating to another source.
- A whole source fails — check for an extension update under Browse → Extensions; if none exists and the site errors in WebView too, the source is down or blocking (see 403 / Cloudflare).
- Everything fails with timeouts — network problem or rate limiting. Try a different network and a smaller update batch.
The battery setting that fixes “update just stops”
Android aggressively stops background apps. If updates start fine and quietly die, set Mihon’s battery usage to Unrestricted in the system app settings, and keep the phone charging during very large first updates. The same setting fixes stalled downloads — see downloads failing.
Make updates smaller and smarter
- Restrict automatic library updates to the categories you are actively reading (Settings → Library).
- Exclude completed series and series on long hiatus from global updates — they waste requests and trigger rate limits.
- Update extensions before a big library run, not after: outdated extensions are the most common per-source failure.
Duplicates and old databases
Libraries carried since Tachiyomi days can contain duplicate entries that slow updates dramatically — Mihon 0.21.1 fixed updates taking up to hours on duplicate-heavy libraries from 0.20.x, and tidying duplicates still helps. See library cleanup. If an update after an app upgrade leaves Mihon frozen on its updating screen instead, that is a separate known issue with its own page: stuck on updating screen.
Related: all troubleshooting guides