The release of Assassins Creed Unit has been plagued with problems. The game was horribly glitchy, there were bugs galore and it was plagued with performance problems. It has really been embarrassing for Ubisoft and for good reason. However, they have been trying hard to fix it ever since.
Patch 4 addresses a large number of issues which is fitting given it's a large patch at 6.7GB. The issues addressed in the patch include performance and stability fixes as well as world issues such as collision detection. There are also a number of PC specific fixes such as fixes for TXAA and PCSS issues as well as texture fixes on MSAA-4x, 8x and TXAA settings.
While these are very welcome Xbox One owners should be aware that there is currently an issues with users who have previously downloaded and applied Patch 3. The update says that 40GB of data needs to be downloaded. Essentially the Xbox is trying to download the whole game again. Ubisoft are working with Microsoft to resolve this but in the meantime a work around is available to owners of the disc version.
To see the complete list of issues addressed in the patch go to forums.ubi.com
The patch is currently available for Xbox One and PS4 owners with the PC version being available later this week.