Bug/Issue Game crashes erratically and inventory displaces items when cycling through

Hi there, my brother and I recently started playing Stardew Valley v1.4.5 together in multiplayer mode. We purchased the game on GOG, and are running the game directly without GOG galaxy, and I am using a PC with Win10 64-bit to host the game. We've clocked a little over 100 hours of game play with no issues. We have not used any mods as well.

2 days ago however, our game started crashing erratically.

Since the game first crashed, I have observed one main problem in my character's inventory (my brother does not have this issue). When I tab to cycle through the 3 "pages" of my inventory, my items are automatically displaced by one box each time. E.g. If my Return Scepter is in Box 1, after I tab through 3 times to return to the same "page", it will now be in Box 2, with all items shifting down by one box. This happens whether or not my inventory is full or only has one item inside. Occasionally, I also notice that an item will disappear and I have to tab to cycle through the inventory again until the item appears.

I have attached to this post the 7 error log files we have gotten so far in the past 2 days while playing. All the error logs contain the same message, "Message: Index was out of range. Must be non-negative and less than the size of the collection."

So far we have not observed that any one action triggers our game to crash. Sometimes, it is when I open a chest to retrieve/place things inside but other times it can be when I'm dismounting from my horse, or farming and cycling through my inventory for tools, etc.

This has been very disruptive to our game play and it is a very unfortunate thing to happen to us so late in our game progress. I'm hoping someone who has experienced a similar issue is able to help!