I found an old build of MCPF on my computer, and modified it so that the logs you send me would contain more information so I can help you in case it doesn't work.
However, this unreleased version is dependant of a server which is now down.
This little webpage tells you how to download everything yourself to avoid MCPF failing.

1. download the software here
2. download the patches here
3. copy MCPF to Applications folder
4. type in terminal mkdir -p ~/Library/MCPF/Downloads && cd ~/Library/MCPF/Downloads && tar -xvf ~/Downloads/mcpfOldPatches.tar.gz. You should see files extracting.
5. If you want to install OS X Mavericks or later, you need to download the kernel, like this cd ~/Library/MCPF/Downloads && curl -O http://macpostfactor.toile-libre.org/AppFiles/osx_kernels/10.9. You of course need to replace 10.9 by the correct version number (Latest Mavericks would be 10.9.5; latest Yosemite 10.10.5; latest El Capitan 10.11.6)
6. run MacPostFactor, which should be able to install or create USB key

Again, this version was not released. It may contain bugs I don't remember.
Use it with caution.
Creating a USB installer is recommended.
For those who want to install OS X Mountain Lion 10.8.*, you can also use MLPF.