NPC interaction = Hard Crash with Reboot

I am experiencing hard crash/reboot when talking to NPCs in towns, or sometimes when using NPC items, like an anvil.

This happens only the first time I speak to an NPC or interact with an anvil. Subsequent conversations or uses are fine.

My PC will hang, and then reboot.

Older machine, but has no issues in-game outside of this.

Windows 10, 16GB RAM, running on an SSD, and a GTX1660 Super.