The ConfimAccount page says: For MW 1.26, this extension is partially incompatible with the ConfirmEdit extension - it only works for logged on users (obviously, this is not necessary), but for anonymous users it displays an empty screen, but works fine when ConfirmEdit is not used.
This is actually also the case with MW 1.34. None of the remedies described in "ConfirmAccount doesn't work with MW 1.33 and 1.34 [Solved]" worked.