The Viewer fails to open a mgf generated in the latest version of L3DT.
The file was a 4097 .bt imported as a heightmap and generated through the wizard, ie no DM.
I altered the horizontal scale (not sure if this should have been necessary- a bug maybe??). I used the defaults, the minimum lighting and texture settings.
The viewer sits there after File>Open.
I had this problem last week with another file generated in a similar way (can't be sure if it was a .bt or not). I just presumed I'd done something wrong.