Run the following scripts to load the FBX plug-ins through MAXScript:
         
         
            
            FBX Importer
            
            
            
pluginManager.loadClass FBXIMPORTER 
 
         
            
            FBX Exporter
            
            
            
pluginManager.loadClass FBXEXPORTER
Note
                  
                  The 3ds Max FBX plug-in must be loaded before you run any script commands with MAXScript, otherwise an error message occurs.