Do you have the .Net framework installed?  Check again that you have properly installed all components, and especially, that you have installed the gmax gamepack into the gmax\gamepacks folder by copy/pasting the whole thing.

Have you installed the SDK to other than the default location?

I'm having the same problem too. I have read the instructions carefully and to the letter and yet I still get the same issue. I even made sure that the procedure regarding the GUID is understood. But still, I get the same "failed to export" issue. There's also the issue that I can't get the XtoMdl utility to work right. In fact, I can t seem to understand how it works.

Our best bet is to simply wait for someone who really does manage to understand how to export directly from Gmax to FSX.

From what I currently understand, when you export from Gmax [using mdlcommander and middleman], you save the X file that's generated, use XtoMdl to then convert the X file into a mdl file. But I don't think i understood it right. So far, I'm sticking with the old fashion way since FSX has some idea on how to understand FS9-based *.mdl files.

Yup. Mdlcommander and Middleman are standalone utilities that link directly with the Gmax makemdl utility. They both act like a bridge between Gmax and makemdl so that you can gain greater control on how to export your models.

I can't find a link for them as I forgot where I got them from and I normally install them from a flash drive that I have used for so long.

Katahu wrote on Jan 19^th, 2007 at 10:55am:


NO!

You cannot use mdlcommander and middleman with the FS-X export tools.  It is my understanding that one of the "requirements"  imposed by discreet of the relicensing of the gmax tools was that no intermediate file could be recovered.  In other words, supposedly the x file resulting from the gmax export is passed on directly to xtomdl.exe

With 3DSMax7/8, you first export to the x file, then manually compile.