A boundary on this surface could not be autodetected. Revit will impose one, but it may be larger than you want.

The layers you have selected contain both contour lines and non-contour lines (lines of non-constant elevation). You may want to go back and select fewer layers, or you can continue, but the boundary of the site may be larger than you want.

Can't auto-detect boundary. The layers selected contain data that may make the Toposurface look incorrect. For better results, try selecting only those layers that contain relevant 3D info.

No points were found in the file.

Can't make Toposurface from View Specific Imports.

You are importing data into a surface that already contains points. You may want to go back, create a new surface, and import the data into that instead. You can continue, and Revit will sew the meshes together, but the boundary may be larger than you want.

Imported Toposurface Points are located a large distance from the model and might not display properly. Points will be centered on the model instead.

There are too many points on the selected layers of this dataset to place into the toposurface. Try selecting fewer layers to create the surface

The layers you have selected contain more than one mesh. You may want to go back and import the meshes separately. If you continue, the meshes will be combined and a new boundary will be created.

Some rows from the file could not be used.