Sometimes chiseling crashes clients to desktop. On the server side, the following error can be seen 

Exception: Index was outside the bounds of the array. at Vintagestory.GameContent.BlockEntityChisel.SetVoxel(Vec3i voxelPos, Boolean add, IPlayer byPlayer, Byte materialId) in VSSurvivalMod\Systems\Microblock\BEChisel.cs:line 306 at Vintagestory.GameContent.BlockEntityChisel.UpdateVoxel(IPlayer byPlayer, ItemSlot itemslot, Vec3i voxelPos, BlockFacing facing, Boolean isBreak) in VSSurvivalMod\Systems\Microblock\BEChisel.cs:line 135 at Vintagestory.GameContent.BlockEntityChisel.OnReceivedClientPacket(IPlayer player, Int32 packetid, Byte[] data) in VSSurvivalMod\Systems\Microblock\BEChisel.cs:line 240 at Vintagestory.Server.ServerSystemBlockSimulation.HandleBlockEntityPacket(Packet_Client packet, ConnectedClient client) in VintagestoryLib\Server\Systems\World\BlockSimulation.cs:line 339 at Vintagestory.Server.ServerMain.HandleClientPacket_mainthread(ReceivedClientPacket cpk) in VintagestoryLib\Server\ServerMainNetworking.cs:line 238 at Vintagestory.Server.ServerMain.ProcessMain() in VintagestoryLib\Server\ServerMain.cs:line 977