I am getting this exact same error on PC.
I have already verified the installation, which just redownloaded everything. I then couldn't even start the game as it was crashing immediately. I then had to uninstall it, and then reinstall it. after the initial download, play then updated it, and i had to wait hours again for it. This time the game launched, but the error persisted. I then walked around in the world, and got an overlay message from ubisoft, saying the game is fully installed. However - when I went to speak to Sigurd, I still got the error.

I don't know what to try anymore.