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We have received and confirmed reports that some Xbox One players who have previously applied Patch 3 are seeing a 40GB download instead of the expected 6.7GB download. Unfortunately, an issue with the patch downloading process is replacing the entire game instead of just the parts affected by the patch. This is obviously not the expected behavior, and we apologize that many of you will have to wait longer than expected to complete this download. This issue isn't causing any other problems and once the download is completed players will have the most-up-to-date and fully patched version of Assassin's Creed Unity.
We are working with Microsoft on a solution to reduce the total download to the intended size so that you can get back into the game faster, but as of now we have no ETA on when this will be resolved.
Currently there is one known workaround: Owners of the disc version of the game can uninstall the game and reinstall it. On starting the game, the patch process will start with the correct download size.
http://kotaku.com/6-7gb-assassins-creed-unity-patch-issued-to-fix-framera-1671872114
