Polygon with fewer than four coordinate pairs

What the Information System does

It does not accept the polygon: "Polygon geometry types consist of at least four pairs of coordinates and represent an enclosed area" (GeoJSON File Description, Definitions). Three distinct corners plus the repeated first point is the minimum.

A broken example

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "ProducerCountry": "CI",
        "ProductionPlace": "Triangle-ish",
        "Area": 0.5
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [-5.123456, 6.123456],
            [-5.122456, 6.123456],
            [-5.123456, 6.123456]
          ]
        ]
      }
    }
  ]
}

What the checker reports for this file:

1. This polygon has 3 coordinate pairs. A closed polygon needs at least four, because the first pair is repeated at the end., line 14, column 11

Fix it in EUDRplot

1. Open the file in the checker. Each short ring is highlighted on the map with the points it has.
2. Add the missing corners. If the corners were lost in export, export again from the source. If they were never recorded, the plot has to be mapped again.
3. Or use a point. If the plot is four hectares or less, a single point with its Area is accepted instead of a polygon. See point or polygon.

Fix it in QGIS

1. Find the short rings. Select by expression: num_points($geometry) < 4.
2. Add corners, or use centroids. In edit mode, add vertices with the Vertex Tool; or, for plots under four hectares, run Centroids to make a point for each and add its Area.