[Ernesto]

By default the maxwell material editor asigns a name to the new created material, accordingly to one of the image files used, unless you change it manually.
That is very usefull, but it saves the mxm file with a wrong format for instance PNG JPG BMP etc accordingly to that same image file.
It would be better if the Maxwell Material editor would FORCE the material file to be saved in MXM format which is the only valid format in this case.

Ernesto