In Maya LT, you can save scenes with the .mlt format only. To export an FBX file, use File > Export All. (See also Export objects to a new file.) Your .mlt scene files cannot be read by any other application.
You can load .ma and .mb files in Maya LT, however any unsupported nodes are removed. (For example, animation layers are not supported in Maya LT, so animation layers are merged in the imported scene.) If you load scenes that include file references, the referenced objects are automatically loaded in the scene.
To start a new, blank scene file
To open an existing scene file
The Open dialog box appears, open in the scene folder of the current project.
To open a file that was created in a earlier version of Maya, ensure the Ignore Version preference is turned on in the File/Projects preferences. See Files Projects preferences.
To save the current scene file