That's because the latest Wc3 patch made a lot of maps unplayable until they're made compatible with the new changes. Or something like that.
There is no working version of MM&M, and the people who know how to make one are not willing to do it.
You could re-install Wc3, manually download the patches before the patch that made it unusable, and play it on LAN, but of course that would require you to know people willing to go through all that trouble to play it.