Okay, for context, playing DoS:EE on a PS4. Console is a baseline unit, with no external harddrive or other complications. Game is installed via physical disc, and updated to the latest patch version. Not using Cloud saves, playing local single-player.
Recently had a problem with vendors crashing the game the moment I click Triangle to open the trade window. This started shortly after finishing the Twin Dungeons quest. After skimming various forums/topics about the issue, I can definitely rule out "common" causes like too much crafting (I haven't been crafting - all I've done to this point is smelt three iron ores into iron bars), too much play time (I'm only level 5, and I've only been playing for about 10 hours - I'm only on Day 3 in-game), or attempts to constantly refresh vendors. Nor have I left the game running for long periods of time in the background (because I've had issues in the past with DoSII and corrupted save files, I've been deliberately turning my PS4 off fully after playing to clear the PS4 cache).
I HAVE been looting pretty much everything I find everywhere, and selling it back to various vendors. And at the moment I've got about 170 slots worth of inventory full on my lead character (most of which is single items, though 40 or so are stacks of about 2-6, with one mushroom stack being 24). I've also picked up a few chests and brought them back to the Hall of Heroes, where I've stored about 9 items or so).
Upon experimentation, it seems as if the issue might be related to the Twin Dungeons quest itself - namely, it seems to be triggered if I pick up the Round and Square Pendants back up off their pedestals (to keep as souvenirs or sell) before leaving. From my save file where I had finished the quest and looted the four treasure chests and gold, if I leave the dungeon, take the pendants, and return to town, every single vendor (even ones I've never sold to before) immediately crash to blue-screen/desktop the moment I attempt to trade. Going from the exact same save file, if I leave the dungeon and leave the pendants behind, all of the vendors seem to work fine when I return to town.
While it seems like I've solved the problem myself and it won't be an issue as long as I don't take the pendants, I'm just trying to confirm if that IS something that could be the issue, and if simply avoiding it DOES prevent the problem entirely, or if there's some other issue at work in the background that I'm completely missing that might be causing similar problems for me later. I'd rather not just assume everything is OK and then play for another 40+ hours only to have the whole game catastrophically lock up with no way to continue. Knowing for sure what's causing the problem means I can go out of my way to avoid having problems in the future.