Issues with Create TIN from a Polygon Feature Class

[JacquelineAlessi]

Im attempting to use the Create TIN tool to create, well a TIN from a polygon FC. I have made sure that all of the vertexes between the various polygons are aligned. But the tool is failing to complete.

Im having difficulty determining if there are any considerations that I overlooked.

The exact error is "The geometry is legal but certain of its properties cannot be computed"

Help?

[ChrisDonohue__GISP]

I don't know the exact answer, but something I noticed from the tool help may be worth checking on the chance it is what is triggering the error:

TINs used for surface modeling should be constructed using projected coordinate systems. Geographic coordinate systems are not recommended because Delaunay triangulation cannot be guaranteed when the XY coordinates are expressed in angular units, and distance-based calculations, such as slope, volume, and line-of-sight, can produce misleading or incorrect results.

ArcGIS Help 10.1

Chris Donohue, GISP