ITopologicalOperator.Buffer ArcGIS VB.Net ArcObjects does not handle specific buffer distances when the Projected Coordinate System is "South_America_Albers_Equal_Area_Conic".
Redefine the coordinate system of the geometry : Dim pSpatialRefFact As ISpatialReferenceFactory2 = New SpatialReferenceEnvironment Dim pProjection As IProjectedCoordinateSystem = pSpatialRefFact.CreateProjectedCoordinateSystem(102033) 'esriSRProjCS_SAD1969S_AmericaAlbers ' Set the pPolygon to the feature which will generate error pErrorPolygon = pErrorFeature.ShapeCopy ' Redifine the projection pErrorPolygon.Project(pProjection) pTopoOp = pErrorPolygon pErrorBuffer = pTopoOp.Buffer(17000)