Error feedback

PathEngine applies strict validation to ground meshes on export, the idea being that once a mesh has passed validation the run-time pathfinding is guaranteed to work correctly with that mesh.
This page, in the Content Creators Guide, provides a more general discussion of issues relating to this validation.

Error feedback in Maya

In the case of a validation error on export the will pop-up a message box with details about the reason for the error.
This message box will usually include information (in the form of error attributes) to help localise the exact geometry that is causing the error.

For the first error with geometry identifying attributes Maya will automatically set up the component selection set from these attributes. You can then use View -> Frame Selection from the viewport menu to zoom the camera in directly on this geometry.