I have been having trouble exporting .mdl and .bgl files with GMAX. I click "export" the type in the name that I want and select "Flight Sim Scenery Model (bgl)" and hit export. Then a warning pops up about: 

"Fight Sim models are specified in meters. This model is not stored in meters, but the exported file will be in meters. Check to make certain the dimentions of the model are correct."

I click ok, and MakeModel pops up and starts to do something but after a little bit another error appears and says that:

"MakeMDL was not found, or failed to convert the model specified in C:\Program Files\GMAX\meshes\Exit Sign' to a .mdl file. Check your system path to ensureMakeMDL is on it."

Then:

"Export Module Failure"

I click ok and GMAX goes back to how it was before I tried to export.

Does anyone know why this is happening? I am using 2004 MakeMdl.