This is a known issue in the digital version of the game (Steam and GOG).
I had previously provided links to a couple of my saves (from the disk version), for someone who ran into this problem, but didn't have any saves before that to revert back to. Another person found that they could fix the crash by replacing the world and objects files in their save with those from one of mine. There were changes to the story and data.000 file, as well, so I didn't try replacing other files when this was first reported.
They replaced both the .0 and .1 files, though very likely only the .0 files would be necessary (the .0 files keep track of information for the main game areas, while .1 is for the battlefields).
The world.* files keep track of doors/walls/buildings, etc (including quest opened locations), and items directly on the ground. That person was able to complete the game successfully, and did not notice any issues from the replaced world files (only visited the BF for the traders, so didn't check the dungeons).
Here is a link for a save just before I completed the amulet quest
However, since you can do that level in whatever order you wish, it might be easier to start again from the beginning
than figure out what I had already done (though that may just involve talking to everyone again).
Extract one or both downloaded zip files into your '..\SteamApps\common\beyond_divinity\savegames' folder (or similarly for the GOG install path).
Make a copy of your latest save folder if you wish to try replacing the world.0 and objects.0 files.
At that point I had the hero as a crossbow archer and the DK using a 2 handed sword (would have been better to make the DK a bow archer, since he doesn't need strength for armour).
You can switch from normal arrows to power arrows. I was hording them out of habit (special arrows were rarer and more expensive in the unpatched disk release, and BF merchant inventories didn't restock each time you entered the BF) and wasn't having problems, so didn't really need the extra damage. There is one fight in a confined space later that using splitting arrows for is quite effective, especially if you set up a crossfire with the hero and act 1 summoning doll both using them. I collected other special arrows, but never bothered switching to match an opponent's weakness, where applicable.
Both characters have some spare stat and skill points, so you can make some adjustments to their builds. There should be enough gold to unlearn a couple skills, as well.