Error when saving as geoparquet

[EmileSonneveld]

  File "/opt/openeo/lib/python3.8/site-packages/openeogeotrellis/deploy/batch_job.py", line 385, in run_job
    the_assets_metadata = result.write_assets(str(output_file))
  File "/opt/openeo/lib/python3.8/site-packages/openeo_driver/save_result.py", line 341, in write_assets
    self.to_geoparquet(filename)
  File "/opt/openeo/lib/python3.8/site-packages/openeo_driver/save_result.py", line 604, in to_geoparquet
    band_names = [f"band_{i}" for i in range(n_band_values)]
TypeError: 'NoneType' object cannot be interpreted as an integer

{
  "process_graph": {
    "aggregatespatial1": {
      "arguments": {
        "data": {"from_node": "loadcollection1"},
        "geometries": {
          "features": [
            {
              "geometry": {
                "coordinates": [
                  [
                    [22.545181, 77.746904],
                    [22.545181, 77.746704],
                    [22.544981, 77.746704],
                    [22.544981, 77.746904],
                    [22.545181, 77.746904]
                  ]
                ],
                "type": "Polygon"
              },
              "id": "0",
              "properties": {},
              "type": "Feature"
            }
          ],
          "type": "FeatureCollection"
        },
        "reducer": {
          "process_graph": {
            "mean2": {
              "arguments": {"data": {"from_parameter": "data"}},
              "process_id": "mean",
              "result": true
            }
          }
        }
      },
      "process_id": "aggregate_spatial"
    },
    "loadcollection1": {
      "arguments": {
        "bands": ["B02"],
        "id": "SENTINEL2_L2A",
        "spatial_extent": null,
        "temporal_extent": ["2019-04-30", "2019-04-30"]
      },
      "process_id": "load_collection"
    },
    "saveresult1": {
      "arguments": {"data": {"from_node": "aggregatespatial1"}, "format": "Parquet"},
      "process_id": "save_result",
      "result": true
    }
  }
}

[EmileSonneveld]

Workaround is to request larger polygons.