System.ArgumentOutOfRangeException - SMSG_UPDATE_OBJECT

Got the following error when it was parsing SMSG_UPDATE_OBJECT for the creature spawns when I parsed a sniff from 5.3.0 16992

Detected build: V5_3_0_16992
Detected locale: enUS
Targeted database: BattleForAzeroth

System.ArgumentOutOfRangeException
Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')
The actual value was -1.
at System.Collections.Generic.SortedList2.GetKey(Int32 index) at System.Collections.Generic.SortedList2.KeyList.get_Item(Int32 index)
at WowPacketParser.Enums.Version.UpdateFields.GetUpdateFieldName[T](Int32 field) in D:\WowPacketParser-master\WowPacketParser\Enums\Version\UpdateFields.cs:line 165
at WowPacketParser.Parsing.Parsers.UpdateHandler.ReadDynamicValuesUpdateBlock(Packet packet, ObjectType type, Object index, Boolean isCreating, Dictionary`2 oldValues) in D:\WowPacketParser-master\WowPacketParser\Parsing\Parsers\UpdateHandler.cs:line 487
at WowPacketParser.Parsing.Parsers.UpdateHandler.ReadDynamicValuesUpdateBlockOnCreate(Packet packet, ObjectType type, Object index) in D:\WowPacketParser-master\WowPacketParser\Parsing\Parsers\UpdateHandler.cs:line 113
at WowPacketParserModule.V5_3_0_16981.Parsers.UpdateHandler.ReadCreateObjectBlock(Packet packet, WowGuid guid, UInt32 map, Object index) in D:\WowPacketParser-master\WowPacketParserModule.V5_3_0_16981\Parsers\UpdateHandler.cs:line 56
at WowPacketParserModule.V5_3_0_16981.Parsers.UpdateHandler.HandleUpdateObject(Packet packet) in D:\WowPacketParser-master\WowPacketParserModule.V5_3_0_16981\Parsers\UpdateHandler.cs:line 39
at WowPacketParser.Parsing.Handler.Parse(Packet packet, Boolean isMultiple) in D:\WowPacketParser-master\WowPacketParser\Parsing\Handler.cs:line 149

Start with Enums/Version/UpdateFields.cs at GetUpdateFieldName and Parsing/Parsers/UpdateHandler.cs at ReadDynamicValuesUpdateBlock. Reproduce the V5_3_0_16992 creature-spawn parse and compare the detected build with the V5_3_0_16981 module shown in the stack trace. Done means the packet parses without the reported index exception.