While trying to clip a layer with another polygon layer, I received the message that it contained invalid geometries. I used the Topology Checker tool under Vector/Topology Checker and it confirmed that there was a geometry error, but it only indicated which feature contained the error. It did not show what or where the error was. I tried using the Check Geometries tool under Vector/Geometry Tools and tried checking various options but could not find the error. One of the options kept crashing QGIS. I then tried the Check Validity tool under Vector/Geometry Tools (there were two Geometry Tools under Vector for some reason, and and it was under the 2nd Geometry Tools). When I ran it, it kept giving an error "-2147483645 See log for more detail" but this message was in the log so I don't know what it means. Here is a link to the shapefile:
<http://brucewiland.com/download/invalid_geometry.zip>

Can anyone tell me what the invalid geometry is and if there is a better tool to find it?

Using QGIS 2.18.18