Description
You may have coincident polygons. This error can also be due to the boundary of the polygons being nearly identical, or it can be due to two polygons being very close to each other and very small compared to the rest of the polygons.
Solution
Use the Find Identical and Delete Identical tools to locate and delete the coincident polygons. If the Find Identical tool does not find any coincident polygons, keep lowering the lattice spacing parameter until the software can differentiate all of the polygons.