I have just fixed some bugs in the 3DS exporter of ModelConverterX. The main issue solved is that complex objects often could not be imported into GMax. Without going into too much technical details, this was caused by some variables being stored as a short, allowing a maximum value of 65535. Some object parts had more triangles or vertices than this limit and that resulted in the error when importing. This has now be been fixed and those model parts will be split when exporting.
Another improvement I made to the 3DS exporter is that the night textures and bump textures are now also written to the material when exporting.
For future improvement of the 3DS exporter I still have the wish to add animations as well, but that is a little lower on the priority list at the moment. And another 3DS related wish is to have an importer for the 3DS format as well.