Short answer: check three things in this order — (1) Mihon’s battery mode is set to Unrestricted, (2) the app still has access to its storage folder and the device has free space, (3) the source itself loads (a source returning 403 fails downloads exactly like it fails browsing). Most download failures are one of these three.
Downloads stall or stop when the screen is off
This is Android battery optimization killing the download service. Set Mihon to Unrestricted battery use in system settings, and disable any “battery saver” for the download session. If downloads only run while the app is open on screen, this was your problem.
Downloads error instantly
- Storage access lost: after system updates or folder moves, Mihon can lose permission to its storage location. Re-select it under Settings → Advanced → Storage location and grant access again.
- Out of space: manga chapters add up — check free space, and clear chapters you have finished (managing downloads).
- Corrupt queue entry: cancel the failed item in the Downloads queue and queue the chapter again.
Downloads fail for one source only
Open the source and try to read a chapter online. If reading also fails with 403 or a Cloudflare page, the downloads are failing for the same reason — follow 403 fixes or Cloudflare fixes. If reading works but downloads fail, update the extension; download paths break more often than reading paths when a site changes.
Downloads crawl or time out on mobile data
- Check for a Wi-Fi-only setting in download options that pauses the queue on mobile data.
- A VPN or DNS filter can throttle image hosts; test one chapter with it off (and see our VPN notes for networks that interfere).
- Download fewer chapters at once — parallel queues trip source rate limits, which look identical to slow downloads.
Related: all troubleshooting guides · offline reading guide