okay, if level is exported as MDL, and the destination directory is set to the same as the place of wmb, and saving external textures is not checked (because that causes a nice crash), it works, except for textures having an alpha channel: they are stored inside the MDL, but not assigned to surfaces, so it should be made manually in MED, which would be a nightmare in case of some hundreds of trees...
moreover, exporting the MDL from MED as FBX makes 8x8x3 sized textures from the alpha textures. and this FBX cannot be read by WED. 3DSMAX can (so probably Maya too), but only without textures, which is the same as using the old FBX 2005 exporter of WED.
end of monologue.
any idea? does Pro version includes a fine FBX exporter in WED at all?