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Unsupported coordinate system

Fix the unsupported coordinate system error. Convert the file to EPSG:4326 or EPSG:3857 in another tool, then import it again.

If processing reports an unsupported coordinate system, MangoMap cannot reproject the file from its current CRS. Convert the file to EPSG:4326 or EPSG:3857 in another tool, then import it again.

Most likely cause: file uses a regional or custom projection

MangoMap reads the input coordinate system from your file (.prj for shapefiles, the GeoJSON crs member, the embedded SRS for other formats). The error appears when the projection in your file isn’t one MangoMap recognises — typically a custom datum, a regional grid, or a vendor-specific code.

How to verify.

Check the projection declared in your file:

  • Shapefile: open the .prj in any text editor. The first part of the WKT is the projection name (e.g. PROJCS["NAD83 / Wisconsin South...").
  • GeoJSON: look for a "crs" member at the top level. Standard GeoJSON should not include it; if it does, the value identifies the projection.
  • Other formats: open in QGIS (Layer → Add Vector Layer); the layer’s CRS is shown in the bottom-right of the QGIS window.

MangoMap can transform many recognised coordinate systems. Reproject only when the declared CRS is malformed or the import reports that it is unsupported.

Fix.

Reproject to EPSG:4326 before re-importing.

In QGIS:

  1. Add the file as a layer.
  2. Right-click the layer → Export → Save Features As.
  3. Set CRS to EPSG:4326.
  4. Save and upload the new file to MangoMap.

On the command line: run the command for your file type.

  • Shapefile:

    $ ogr2ogr -t_srs EPSG:4326 output.shp input.shp

  • GeoJSON:

    $ ogr2ogr -t_srs EPSG:4326 output.geojson input.geojson

  • Raster (GeoTIFF):

    $ gdalwarp -t_srs EPSG:4326 input.tif output.tif

Less common: .prj file says one thing, data is in another

Occasionally a shapefile has a .prj that doesn’t match the actual coordinates — typically because the file was reprojected with a tool that didn’t update the .prj. MangoMap trusts the .prj, so the data ends up in the wrong location even if processing succeeds.

How to verify.

Open the shapefile in QGIS. If the features draw in the wrong place when QGIS reads the .prj, the declaration is wrong.

Fix.

Set the correct CRS in QGIS (Layer → Set CRS), then export to a new shapefile. The new export’s .prj will match the data.

If none of the above

If your data is already in EPSG:4326 or EPSG:3857 but you still see this error, the file may have a malformed CRS declaration. Open in QGIS, confirm the layer reads correctly, then export again — the QGIS export will write a clean CRS.