How to Build Offline Maps with Mobile Atlas Creator (Step‑by‑Step)

Mobile Atlas Creator: Troubleshooting Common Problems

1) Most common issues and quick fixes

• Unrecoverable / missing tiles (HTTP 404 or similar):
  • Check MOBAC debug log (Debug → Show log) for failing tile URLs and HTTP codes.
  • Re-run atlas for affected zoom levels; increase retry count (Atlas → Settings).
  • Verify the map source is up-to-date and supported (some providers remove tiles at high zoom).
• Coverage looks complete but tiles still missing:
  • After changing zoom, click Show coverage again — selection redraw is required.
  • Use the log to find exact failed tiles; re-create selection/profile and retry only that area.
• Access blocked / rate limiting from map providers:
  • Reduce selected area and/or lower max zoom.
  • Use map providers that permit bulk downloading or run your own tile server.
  • Respect tile usage policies (e.g., OpenStreetMap tile usage limits).
• Wrong rendering / missing labels with Mapsforge vector rendering:
  • Differences may appear between preview and exported tiles due to label placement across tile borders.
  • Export at fewer zoom levels (or smaller areas) to reduce label-splitting artifacts.
• Atlas format incompatibility on target app (OsmAnd, OruxMaps, Osmdroid, etc.):
  • Choose the correct output format for the target app (e.g., OSMAND SQLite for OsmAnd).
  • Note MOBAC ignores some settings per output format (tile size, layer names); consult README.

2) How to diagnose systematically

1. Open MOBAC error log: %APPDATA%\Mobile Atlas Creator\Mobile Atlas Creator.log (Windows) or ~/.mobac/ (Linux/Mac).
2. Enable advanced logging (place log4j.xml next to MOBAC jar) if needed.
3. Reproduce the export and review log entries for “Retry limit reached”, HTTP status, missing file paths.
4. Identify whether failures are network/provider (HTTP 4xx/5xx) or local (IO, disk space, Java errors).

3) Fixes for specific error types

• HTTP 404 / “No data found”: map provider lacks tiles at that zoom/location — lower zoom or choose different source.
• Retry limit reached / transient network errors: increase retries, ensure stable internet, or run overnight with small batches.
• Permission / blocked by provider: switch to an allowed provider, self-host tiles, or reduce request rate.
• OutOfMemory / Java crashes: increase Java heap (run: java -Xmx2G -jar mobac.jar) or reduce selection size.
• Corrupt atlas files / incompatible format: delete partial atlas and re-create using correct format for the target app.

4) Best practices to avoid problems

• Use profiles: save and reload map selections to re-run only failing areas.
• Export in small batches (split large regions) and limit max zoom to where tiles are available.
• Prefer official or permissive tile providers, or host your own tile renderer if you need many tiles.
• Keep MOBAC updated and consult its README for format-specific limitations (mobac.sourceforge.io).

5) When to seek help / what to include in bug reports

• Include MOBAC version, Java version, OS, exact atlas format, map source name, selection area/zoom, and the log excerpt showing errors.
• For provider-related blocks, include sample failing URL and HTTP response.

If you want, I can produce a short checklist you can run through next time you hit errors (one-page).