Problem downloading Gold Edition (The Sims 3)

I am having problems downloading. Uploading from disk. Includes 3 discs. Two double-sided, for a total of 5 discs. When installing from a disk and (as I was advised to first drop the contents of all disks into one folder, and then upload from there), problems arise with disk 5. One of the two files cannot be read. Please tell me what to do? I have already changed the disk, but the same problem.