APIV3 GetBlockTransactions throws JSON deserialization error.

[jamescarter-le]

When using HTTP_TONCENTERAPIV3 and calling client.GetBlockTransactions the application can fail to deserialize the response:

Newtonsoft.Json.JsonSerializationException: Error converting value {null} to type 'System.Int64'. Path 'transactions[1].in_msg.created_lt', line 1, position 3792.
 ---> System.InvalidCastException: Null object cannot be converted to a value type.
   at System.Convert.ChangeType(Object value, Type conversionType, IFormatProvider provider)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.EnsureType(JsonReader reader, Object value, CultureInfo culture, JsonContract contract, Type targetType)
   --- End of inner exception stack trace ---
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.EnsureType(JsonReader reader, Object value, CultureInfo culture, JsonContract contract, Type targetType)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateList(IList list, JsonReader reader, JsonArrayContract contract, JsonProperty containerProperty, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateList(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, Object existingValue, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
   at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
   at Newtonsoft.Json.JsonSerializer.Deserialize(JsonReader reader, Type objectType)
   at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
   at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
   at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value)
   at TonSdk.Client.HttpApiV3.GetTransactions(Address address, UInt32 limit, Nullable`1 lt, String hash, Nullable`1 to_lt, Nullable`1 archival)
   at TonSdk.Client.TonClient.GetTransactions(Address address, UInt32 limit, Nullable`1 lt, String hash, Nullable`1 to_lt, Nullable`1 archival)
   at Program.<Main>$(String[] args) in C:\Scratch\TonTestSdk\Program.cs:line 44

Here is the response from TonCenter:
toncenter.com/api/v3/transactions?account=EQDNDaIHcH22lEqZgVritZNp860-KCzGf-s1hWMADf8ky1YS&offset=0&limit=10&sort=desc&start_lt=47392202000001

{
 "transactions": [
     {
         "account": "0:CD0DA207707DB6944A99815AE2B59369F3AD3E282CC67FEB358563000DFF24CB",
         "hash": "jhhKK/c3DQr+zNz3iETF450uZfwgznxHyv2UcnlLnTc=",
         "lt": "47392202000021",
         "now": 1719582529,
         "orig_status": "active",
         "end_status": "active",
         "total_fees": "396400",
         "prev_trans_hash": "vV3YFlqAdL/1o1dpwawqFuLgXjfP34O1YtJaTmV1AN0=",
         "prev_trans_lt": "47392202000001",
         "description": {
             "type": "ord",
             "action": {
                 "valid": true,
                 "success": true,
                 "no_funds": false,
                 "result_code": 0,
                 "tot_actions": 0,
                 "msgs_created": 0,
                 "spec_actions": 0,
                 "tot_msg_size": {
                     "bits": "0",
                     "cells": "0"
                 },
                 "status_change": "unchanged",
                 "skipped_actions": 0,
                 "action_list_hash": "lqKW0iTyhcZ77pPDD4owkVfw2qNdxbh+QQt4YwoJz8c="
             },
             "aborted": false,
             "credit_ph": {
                 "credit": "4618000"
             },
             "destroyed": false,
             "compute_ph": {
                 "mode": 0,
                 "type": "vm",
                 "success": true,
                 "gas_fees": "396400",
                 "gas_used": "991",
                 "vm_steps": 29,
                 "exit_code": 0,
                 "gas_limit": "11545",
                 "msg_state_used": false,
                 "account_activated": false,
                 "vm_init_state_hash": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
                 "vm_final_state_hash": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="
             },
             "storage_ph": {
                 "status_change": "unchanged",
                 "storage_fees_collected": "0"
             },
             "credit_first": false
         },
         "block_ref": {
             "workchain": 0,
             "shard": "C000000000000000",
             "seqno": 44272274
         },
         "in_msg": {
             "hash": "FH0fOhm9bbGuaapRGaIlwwttOu44frYSOCPi1j/7UME=",
             "source": "0:A107678CA051B84E1B84B19E9E86504F2895CE8CDC6547907BA8A64D188BF6E7",
             "destination": "0:CD0DA207707DB6944A99815AE2B59369F3AD3E282CC67FEB358563000DFF24CB",
             "value": "4618000",
             "fwd_fee": "301869",
             "ihr_fee": "0",
             "created_lt": "47392202000020",
             "created_at": "1719582529",
             "opcode": "0x00000000",
             "ihr_disabled": true,
             "bounce": true,
             "bounced": false,
             "import_fee": null,
             "message_content": {
                 "hash": "P+k4lxWGmOTUc7dEFNdJNxaw/DpwMQk0hz8AGdqsyrQ=",
                 "body": "te6cckEBAQEABgAACAAAAADjAK8P",
                 "decoded": {
                     "type": "text_comment",
                     "comment": ""
                 }
             },
             "init_state": null
         },
         "out_msgs": [],
         "account_state_before": {
             "hash": "tqHJ5o3QIwuBLQuDrngHVBXyQTjGd99LmuHzfgrYtag=",
             "balance": null,
             "account_status": null,
             "frozen_hash": null,
             "code_hash": null,
             "data_hash": null
         },
         "account_state_after": {
             "hash": "2FDwaPJtDGbQkdbK4+doQGSSzYnfLse+W+YUvB/7C+Y=",
             "balance": "919285349",
             "account_status": "active",
             "frozen_hash": null,
             "code_hash": "/rX/aCDi/w2Ug+fg1iyBfYRniftK5YDIeIZtlZ2r1cA=",
             "data_hash": "nnH9X9M76s+VInxPcKUXTIYvitguPyXvWySUOhaYyPc="
         },
         "mc_block_seqno": 38657593
     },
     {
         "account": "0:CD0DA207707DB6944A99815AE2B59369F3AD3E282CC67FEB358563000DFF24CB",
         "hash": "vV3YFlqAdL/1o1dpwawqFuLgXjfP34O1YtJaTmV1AN0=",
         "lt": "47392202000001",
         "now": 1719582529,
         "orig_status": "active",
         "end_status": "active",
         "total_fees": "2198551",
         "prev_trans_hash": "i+09/CUCPmtruJeFzWGWSWFnYoUv/wC/2Vz5lai5V0c=",
         "prev_trans_lt": "47392052000001",
         "description": {
             "type": "ord",
             "action": {
                 "valid": true,
                 "success": true,
                 "no_funds": false,
                 "result_code": 0,
                 "tot_actions": 1,
                 "msgs_created": 1,
                 "spec_actions": 0,
                 "tot_msg_size": {
                     "bits": "865",
                     "cells": "2"
                 },
                 "status_change": "unchanged",
                 "total_fwd_fees": "494400",
                 "skipped_actions": 0,
                 "action_list_hash": "gNAEUJwALEnY8AB1W+LYfaQfiVHQW2KmzefDvRd0ZeE=",
                 "total_action_fees": "164797"
             },
             "aborted": false,
             "credit_ph": {
                 "credit": "139775004705023"
             },
             "destroyed": false,
             "compute_ph": {
                 "mode": 0,
                 "type": "vm",
                 "success": true,
                 "gas_fees": "1323200",
                 "gas_used": "3308",
                 "vm_steps": 68,
                 "exit_code": 0,
                 "gas_limit": "0",
                 "gas_credit": "10000",
                 "msg_state_used": false,
                 "account_activated": false,
                 "vm_init_state_hash": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
                 "vm_final_state_hash": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="
             },
             "storage_ph": {
                 "status_change": "unchanged",
                 "storage_fees_collected": "154"
             },
             "credit_first": true
         },
         "block_ref": {
             "workchain": 0,
             "shard": "C000000000000000",
             "seqno": 44272274
         },
         "in_msg": {
             "hash": "6V/uUnkjlJBBVWXaCnVqr9lYH0gT/Dyup8TdqHd4nR4=",
             "source": null,
             "destination": "0:CD0DA207707DB6944A99815AE2B59369F3AD3E282CC67FEB358563000DFF24CB",
             "value": null,
             "fwd_fee": null,
             "ihr_fee": null,
             "created_lt": null,
             "created_at": null,
             "opcode": "0xd59bc7a0",
             "ihr_disabled": null,
             "bounce": null,
             "bounced": null,
             "import_fee": "0",
             "message_content": {
                 "hash": "+4NRNR5y8z0ThSEDWuMlo6dwuLMZs1KEdtHby4orLW0=",
                 "body": "te6cckEBAwEAngABnNWbx6Bmcuoe0+mxwPUBgqkoynQcl9QSwlXLwHDWxL4pFQwo8mMFJFETOwEAaoP0NZSsSG1C3S6gfHze6IyzegopqaMXZn7AYgAAAJoAAwEBbmIAUIOzxlAo3CcNwljPT0MoJ5RK50ZuMqPIPdRTJoxF+3Ob0JAAAAAAAAAAAAAAAAAAAGEVNRQCACIzMzYzMTcxOTU4MjUwODg1NGtQ55c=",
                 "decoded": null
             },
             "init_state": null
         },
         "out_msgs": [
             {
                 "hash": "dO0JhK3kNAOOTlUQjIq8jkP0pkKS9NZYpDVl2Fz5U6w=",
                 "source": "0:CD0DA207707DB6944A99815AE2B59369F3AD3E282CC67FEB358563000DFF24CB",
                 "destination": "0:A107678CA051B84E1B84B19E9E86504F2895CE8CDC6547907BA8A64D188BF6E7",
                 "value": "8000000",
                 "fwd_fee": "329603",
                 "ihr_fee": "0",
                 "created_lt": "47392202000002",
                 "created_at": "1719582529",
                 "opcode": "0x61153514",
                 "ihr_disabled": true,
                 "bounce": true,
                 "bounced": false,
                 "import_fee": null,
                 "message_content": {
                     "hash": "XwFfeHYUwpqBQd5NjKJSJKV50pbRJUh+yIy2FujYtmM=",
                     "body": "te6cckEBAgEAGgABCGEVNRQBACIzMzYzMTcxOTU4MjUwODg1NP/X3aw=",
                     "decoded": null
                 },
                 "init_state": null
             }
         ],
         "account_state_before": {
             "hash": "BsC2e1KhSBeaeyyjK67HbmRO9yV+ZhI3HdwNCaB7OhA=",
             "balance": "925591903",
             "account_status": "active",
             "frozen_hash": null,
             "code_hash": "/rX/aCDi/w2Ug+fg1iyBfYRniftK5YDIeIZtlZ2r1cA=",
             "data_hash": "pOxOXfiMGmbUc84kVE0thv63blpgoFhfq4AdIvNdAAY="
         },
         "account_state_after": {
             "hash": "tqHJ5o3QIwuBLQuDrngHVBXyQTjGd99LmuHzfgrYtag=",
             "balance": null,
             "account_status": null,
             "frozen_hash": null,
             "code_hash": null,
             "data_hash": null
         },
         "mc_block_seqno": 38657593
     }
 ],
 "address_book": {
     "0:CD0DA207707DB6944A99815AE2B59369F3AD3E282CC67FEB358563000DFF24CB": {
         "user_friendly": "UQDNDaIHcH22lEqZgVritZNp860-KCzGf-s1hWMADf8kywvX"
     },
     "0:A107678CA051B84E1B84B19E9E86504F2895CE8CDC6547907BA8A64D188BF6E7": {
         "user_friendly": "EQChB2eMoFG4ThuEsZ6ehlBPKJXOjNxlR5B7qKZNGIv256Da"
     }
 }
}