The most common Rainbow Six Siege errors that were reported are: Crashes, UPlay issues and problems with the FPS, like Slow FPS and FPS Drops. There are also some that complained about a few minor bugs with the game that can be easily fixed.
Until now the game got a lot of positive reviews, like 1,000 reviews, and players are saying that it works great. Tom Clancy’s Rainbow Six Siege was released on Steam a couple days ago and it seems to be a great game with just a few minor issues.