Invalid geometries are loaded into a file geodatabase under certain circumstances

· Self intersecting polygons
Multipart polygons can not overlap within a geometry.

· Unclosed polygons
All parts of a polygon must close. The last vertex of a polygon ring should be the same as the last vertex. While the polygon fill algorithm used in ArcGIS draw polygons correctly that do not close correctly, the geometries remain invalid.

· Single point polygons and lines
Polygon must be composed of at least three points. Lines must be composed of at least two point.

· Incorrect polygon ring direction
The vertices of the outer ring of each polygon must be in clockwise order. A polygon may contain multiple outer rings. Holes are counter clockwise. If the outer rings or holes are not following the proper ring direction, the geometry is invalid.