EA’s advised that there is a known issue with the latest version of Origin (v8.5) which is impacting customers who purchased Mass Effect 3 digital download from retailers other than Origin.
During installation, customers will likely see a message indicating a “disc read error”. If the customer simply clicks “Try Again” in the error dialogue that should bypass the error and continue the installation.
EA’s advise that it’s aware of the issue and hopes to resolve it soon. Meanwhile, If the problem persists, you should contact help.ea.com.