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Unfortunately Firefox has cached a redirect that no longer works. Please clear the cache of your browser and continue your visit.

What I did (YMMV):

Menu 'Edit', option 'Preferences', tab 'Privacy', link 'clear your recent history'.
Select time range to clear: 'Everything', select only the checkbox 'cache', unselect the others, and push the button 'Clear now'.
Close the preferences window and go to http://proba2.oma.be