I cannot save or load a game. I can only Quit a game and then continue it. Save and Load plates are Empty (there is nothing on them) and are rigid (fixed) too.

This may have already been answered in this thread below.

http://www.gog.com/forum/master_of_magic/saving_problems_and_some_smaller_stuff

Basically you need to be in game and click on one of the empty slots and type in a name. Until you do that there will be no save/load buttons.

IIRC, it's possible to save a game with no title. That makes it effectively invisible unless you click directly on its slot.

Just always be sure to type in a name for the save.