Is you disk new? I had all sorts of issues with a so known clean-to-the-human-eye disk, that once found it self on the floor. That was it, I was not able to load any bad wheather (rain), no new tracks, and removing all the up to then updates brought me in this situation.Upgrading the hard drive didn't help, neither trying the unbeknownst damaged disk in another machine either.
After a little over a year in Hiatus, and the fact that the game is now $14.99, The updates were installed successfully and I was able to resume play, with a new disk.