@tpwUK
I'm not using a cracked version, I can give to Michael all the informations regarding my purchase if needed.

@Michael
Your tip about permission indirectly gave me the solution.

I should have mentioned I'm running a triple boot on my MacBook Pro. At first I had a shared HFS+ partition, but for some reason, upgrading to Mavericks messed up with my partitions and even with GRUB with only a grub rescue prompt left at the end.. So I had to restore everything but, for some other reasons, I couldn't restore my shared partition in order for it to be seen by Windows.. So I ended up by extending the Windows partition with the place taken by the old shared partition and having a folder I'm sharing with OSX and Linux. This partition is NTFS though (I've installed the Paragon driver in order for OSX to access it).

Anyway, I've downloaded MoI on the NTFS partition and extracted the zip file there then launched the app directly from there. It didn't worked. Then I copied it into the Application folder and launched it from there. It didn't worked either so I reported the issue here.

Now, by simply copying the zip file into my Documents folder on the OSX/HSF+ partition, then extracting it there and launching the app, it works..

I guess by unzipping the archive on to the NTFS partition the permissions of all the files inside the app package were not set correctly.

Sorry for the noise, albeit this may help someone else someday.

Cheers,
Guy