Overview
This is a very short guide that deals with the crash issues at the end of Chapter 1. Be aware that this guide can contain spoilers.
The issue
Many users reported having their game break entirely after a cutscene at the end of Chapter 1 (after you complete the mission with Loredo). The crash occurs after the ship in the cutscene sails for Kaedwen.
The solution
The only way I was able to solve this was by going back to the point where Roche fights Iorveth (any save after that appears to be corrupt as well). The issue should disappear after that.
Be aware that this issue may occur once again during King Henselt’s cutscene – I would recommend skipping it altogether and just watch it somewhere on YouTube.