How are you launching the Sysdowngrader? Through Browserhax or did you installed Menuhax?
Browserhax site is down for a few days (and will be for the next couple of weeks) so try some mirrors (search gbatemp for "browserhax mirrors" )
OR try the no-browser version (with a CART entrypoint)
Browserhax. I can get into the Homebrew Channel and start Sysdowngrader from there.
Menuhax doesn't seem to install for me. It freezes at 'downloading config...'
As for OoT3DHax? It crashes with the "home menu ropbin is ready" message to home screen.