I hate to be the one to tackle this, but I love McMMM and use it constantly, so I don't want to see someone else have a problem with it.
First of all, have you used McMMM with other mods successfully? If so, then it is just a problem with that particular mod (perhaps a corrupt zip, etc).
If you haven't used McMMM successfully, then maybe it would be beneficial to review this.
One thing to always check is that you aren't dropping a zip file that has file folders inside it into your Mods folder. The mod zip should only have the bmp's inside it (screenshot pics and/or readme's are fine). If you double click the zip file and you are looking at a folder instead of the bmp's, then McMMM won't be able to use it. Drag the bmp's onto the desktop, highlight them, right click and send to a zip file. Then name it whatever you like and use that.
Anyway, that's a start.