keiji, you most probably have to download the Version Switcher.
unless your current version is the same as the version in which the replay was saved, you wont be able to view it.
therefore: 1) check which version the replay was saved. 2) change your version to THAT one 3) try to view the replay.
BTW:
how do you make a Replay that you downloaded work?
i downloaded some but when i try to replay them at my WarCraft they wont work
saying something like
i need the version of that replay's map
even thru i do have the map~