arcgis desktop - How to repair topology of a shapefile?

I performed an object-based image analysis using ENVI EX, and each of the classified features were exported as a shapefile. I transferred those shapefiles into ArcMap 10, and tried to intersect them with other shapefiles of the same area that were acquired from GeoBase.

When I try to run the intersect tool, I get an error message stating that the topology of the shapefiles extracted from ENVI EX are invalid. I tried to turn on the topology tool to repair the topology of those shapefiles, but the buttons are greyed out, and I can't seem to click on them. The topology tool does not work for any of the shapefiles that I have.

Any solutions? How I can I fix the topology and run the intersect?

Answer

I encountered similar issues as well with polygons. Maybe you have a similar problem.

Error Message by ESRI: "Invalid Topology (Incomplete Void Poly)"

Actual Error: "Invalid Geometry"

Fix: Run "Repair Geometry" (changes data in-place, be careful, there is no undo)

What happens is that the error reported is not using the ESRI terminology of Topology/Geometry and confuses everyone. In my case, while the error was talking about topologies, there were no topologies defined (topology as in an ESRI topology). But when I checked the geometry (using the "Check Geometry" tool) I found out that my geometry (as in an ESRI geometry) there were errors.