Null reference exception in CollectibleBehaviorScrapeCrucible while rotating a chiseled block

[satyrnidae]

A player on my server encountered a very odd forced disconnect while trying to rotate a chiseled block with the vanilla Rotate tool mode.

Game version: 1.21.6
SmithingPlus version: 1.8.3
Relevant other mods that are installed on that player's client and the server:

• ChiselWiz 4.0.2 (client)
• QP's Chisel Tools 1.16.2 (server)

I didn't see any verbose debug output for SmithingPlus, just this exception trace in the main server logs:

1.2.2026 15:32:47 [Event] Player Hammersmith got removed. Reason: Threw an exception at the server
1.2.2026 15:32:47 [Error] Exception: Object reference not set to an instance of an object.
   at SmithingPlus.BitsRecovery.CollectibleBehaviorScrapeCrucible.OnHeldInteractStop(Single secondsUsed, ItemSlot slot, EntityAgent byEntity, BlockSelection blockSel, EntitySelection entitySel, EnumHandling& handling) in /_/SmithingPlus/BitsRecovery/CollectibleBehaviorScrapeCrucible.cs:line 51
   at Vintagestory.API.Common.CollectibleObject.OnHeldInteractStop(Single secondsUsed, ItemSlot slot, EntityAgent byEntity, BlockSelection blockSel, EntitySelection entitySel) in VintagestoryApi\Common\Collectible\Collectible.cs:line 1435
   at Vintagestory.Server.ServerSystemInventory.HandleHandInteraction(Packet_Client packet, ConnectedClient client) in VintagestoryLib\Server\Systems\Inventory.cs:line 388
   at Vintagestory.Server.ServerMain.HandleClientPacket_mainthread(ReceivedClientPacket cpk) in VintagestoryLib\Server\ServerMainNetworking.cs:line 280
   at Vintagestory.Server.ServerMain.ProcessMain() in VintagestoryLib\Server\ServerMain.cs:line 934
1.2.2026 15:32:47 [Event] Client 8 disconnected.

Unfortunately it seems rather inconsistent to reproduce. I'll update with more information if I get more crashes.

[satyrnidae]

Update: Looks like it's occurring when the user rotates a chiseled block twice in quick succession. If they wait for a bit to rotate the block a second time they don't crash.

[mattordev]

This has started happening on our server out of the blue - The only changes being that I installed ndlvillagers_2.5.1, ndltreegrowth_1.2.0, Infantrys-dolabra_1.0.5 and DarkVisionV.1.2.0 like 30 minutes ago - although I don't see how any would have caused this to occur - are you also running any of these mods by chance?

Here's the error from my console, as there's no log on the client from my quick search - I believe it's identical anyway:

7.2.2026 23:04:49 [Server Event] Player Phowenix got removed. Reason: Threw an exception at the server
7.2.2026 23:04:49 [Server Error] Exception: Object reference not set to an instance of an object.
   at SmithingPlus.BitsRecovery.CollectibleBehaviorScrapeCrucible.OnHeldInteractStop(Single secondsUsed, ItemSlot slot, EntityAgent byEntity, BlockSelection blockSel, EntitySelection entitySel, EnumHandling& handling) in /_/SmithingPlus/BitsRecovery/CollectibleBehaviorScrapeCrucible.cs:line 51
   at Vintagestory.API.Common.CollectibleObject.OnHeldInteractStop(Single secondsUsed, ItemSlot slot, EntityAgent byEntity, BlockSelection blockSel, EntitySelection entitySel) in VintagestoryApi\Common\Collectible\Collectible.cs:line 1435
   at Vintagestory.Server.ServerSystemInventory.HandleHandInteraction(Packet_Client packet, ConnectedClient client) in VintagestoryLib\Server\Systems\Inventory.cs:line 258
   at Vintagestory.Server.ServerMain.HandleClientPacket_mainthread(ReceivedClientPacket cpk) in VintagestoryLib\Server\ServerMainNetworking.cs:line 280
   at Vintagestory.Server.ServerMain.ProcessMain() in VintagestoryLib\Server\ServerMain.cs:line 934
7.2.2026 23:04:49 [Server Event] Client 9 disconnected.

[satyrnidae]

@mattordev Interesting. I have ndltreegrowth_1.2.0 installed.
I think it might be network-influenced as well, as I have DarkVision installed locally but I'm the only person who hasn't had this happen to them, and I'm on the same network as my server.

[mattordev]

With the network side of it, I wouldn't be so sure - I'm local to my server too but it's crashed me @satyrnidae.

I might try and remove tree growth and test it as my server is low pop at the minute and I can test it relatively quickly (using AMP).

Will report back!

[mattordev]

So, after testing the server with ndltreegrowth_1.2.0 on and off - it remains the same so it's not a culprit any more I don't think. It's so inconsistent though, sometimes it's perfectly fine, other times it's a guaranteed crash. I think the next test would be to run it in a world with ONLY SmithingPlus in and for example QPsChiselTools and see what happens then?