The Patch 4 update was released tonight for Assassin's Creed Unity. The patch is 6.5GB on the PlayStation 4 and reportedly says it's 40GB for the Xbox One version of the game. Why the size difference? No idea. Though it says 40GB some XB1 owners have said it only needs to download the "normal" 6.5GB as the other platforms. The PC patch? It's supposed to also be out, but it hasn't yet been released through Steam. It's alright though, because the game is apparently quite broken still.

Namely, the biggest issue people are noticing is that NPC's are still popping into existence right in front (audio warning) of the player, with some feeling like the issue is worse than it was prior to the patch. Keep in mind that this update was actually delayed. It was supposed to be out yesterday but was pushed back for more QA. Yup...

Changelog for Assassin's Creed Unity for December 16, 2015

Stability, Performance and Save Game
Fixed numerous random crashes both on Campaign and Coop
Implemented multiple optimizations and fixes to improve overall performance
Fixed save issue caused by the companion app on the main menu (loss of data)
Fixed save issue caused by contacts list (crash occurring). Users should now have access to save

Gameplay (navigation, fight, stealth)
Fixed various navigation issues
Fixed issues with lock picking chests
Fixed additional haystack issues

Character, AI and Crowd
Fixed various character, crowd station and NPC issues

Online, Matchmaking, Connectivity and Replication
Fixed various matchmaking and connection issues both in matches and when starting a match.
Fixed various issues with voice chat
Fixed join-in-progress issues
Fixed various replication issues between host and clients
Fixed issues with player rank and COOP/heist rewards
Fixed issues with Helix credits
Fixed issues with the My Club feature

Menus and HUD
Fixed HUD icon issues and issues with map information
Fixed various Initiates issues
Fixed additional issues with notifications

Mission tweaks (campaign, coop and side content)
Fixed various low occurrence walkthrough breaks in both Campaign and COOP
Fixed various NPC issues
Fixed issue with the quest log disappearing for specific side missions

World and 3D
Fixed various collision and mesh issues
Fixed additional issues where player would fall through the world
Fixed specific areas where textures were missing

PC-Specific
Fixed crash on "Quit to Windows" in free roam mode
Fixed crash on accepting multiple "Join the club" requests
Fixed issues with TXAA
Fixed issues with PCSS
Fixed issues with textures on NPCs
Fixed black texture issues on MSAA-4x, MSAA-8x and TXAA
Right Control now can be assigned as a hotkey
Minor UI fixes