Fatal Firepit Error

[l33tmaan]

I normally wouldn't post this since it's happening to my mod, but apparently this is a really nasty bug that should be brought to the developer's attention.

Here's the report:

Spoiler

16.4.2021 08:47:30 [Error] Error thrown trying to serialize block entity Vintagestory.GameContent.BlockEntityFirepit at 500001, 3, 500000, will not save, sorry! Exception: System.NullReferenceException: Object reference not set to an instance of an object.
   at Vintagestory.API.Datastructures.StringArrayAttribute.ToBytes(BinaryWriter stream)
   at Vintagestory.API.Datastructures.TreeAttribute.ToBytes(BinaryWriter stream)
   at Vintagestory.API.Datastructures.TreeAttribute.Clone()
   at Vintagestory.API.Common.ItemStack.GetEmptyClone()
   at Vintagestory.API.Common.InventoryBase.SlotsToTreeAttributes(ItemSlot[] slots, ITreeAttribute tree)
   at Vintagestory.GameContent.BlockEntityContainer.ToTreeAttributes(ITreeAttribute tree)
   at Vintagestory.GameContent.BlockEntityFirepit.ToTreeAttributes(ITreeAttribute tree)
   at Vintagestory.Server.ServerChunk.BeforeSerialization()

So I got the latest exper.dll file from @jakecool19 which caused food made by my cooking pot to not cook - they'd just stay cold. This is with the unsafe files. 
I can't work with a bug like that, so I reverted back to the safe files.

Here's where things get funky. 

I've gone back to the old files and changed nothing else. Now when I cook food made with the cooking pot - it crashes, giving me a rendering error due to the functions of the renderIngredientsByType uh... function. This is despite the fact that these files were working fine last night.

Okay, so maybe it's my fault. I revert back to Expanded Foods 1.3.0. No change.
I revert Vintage Story back to 1.14.7. No change.
I go into my AppData files and delete my VintagestoryData folder and make a fresh world. No change.
I delete Vintage Story from its main directory AND VintagestoryData so there's no trace of anything, then I reinstalled. No change.
I go into the Control Panel > Uninstall a Program and uninstall all of VS, then do a fresh install and use the safe files. Now it works. 

I've had trouble replicating this, but it was a hell of a problem to have.