I tried installing this off a thumb drive/then off the hard-drive with thumb drive connected/and then off hard drive without thumb drive attached and it started to give me an error message similar to "There is no disk in the drive. Please insert a disk into drive \Device\Harddisk#\DR#." Where number was either 3 or 4(but I don't think the exact number matters). The first install caused the error every system start up until I fiddled around in disk management. The second/third install only gave it while running the game. So I think your installer might be trying to reference something on your computer(but it definitely was annoying).
Other problems I have seen though include:
The aforementioned double MWLL folders. (\Mods\MWLL\MWLL\Stuff Here) - Second install I corrected it.
And on initial run sound cut out though I reloaded and it worked.
I tested the Cryhammer Utility and it couldn't tell if I patched to 1,5 (I have disc version).
and If you click repair build in the launcher it thinks I have an old build of MWLL installed.
I'm going to try the regular method now.
I was just hoping for an easy one time install deal with this supposedly being the final build oh well. I'll get back after the normal install goes and see what happens.
Hopefully the updated build has fixed paths and works.