[Bug]: TF400324: Azure DevOps services are not available from server https://dev.azure.com/org

[AjinkyaIG]

I was in the middle of a migration, out of 8631, around 1300 items were migrated already.
And then the process stopped with above error.
First it was for the source ADO org- TF400324: Azure DevOps services are not available from server https://dev.azure.com/source/

Then I tried re-running the migration, then it shows the same error for the target ADO org.

Why is this happening? Have I reached any limit in terms of migration?

Microsoft.TeamFoundation.TeamFoundationServiceUnavailableException: TF400324: Azure DevOps services are not available from server https://dev.azure.com/target/.
Technical information (for administrator):
  The underlying connection was closed: A connection that was expected to be kept alive was closed by the server. ---> System.Net.WebException: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   --- End of inner exception stack trace ---
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.FixedSizeReader.ReadPacket(Byte[] buffer, Int32 offset, Int32 count)
   at System.Net.Security._SslStream.StartFrameHeader(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security._SslStream.StartReading(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security._SslStream.ProcessRead(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.TlsStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.PooledStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.Connection.SyncRead(HttpWebRequest request, Boolean userRetrievedStream, Boolean probeRead)
   --- End of inner exception stack trace ---
   at System.Net.HttpWebRequest.GetResponse()
   at Microsoft.TeamFoundation.Client.Channels.TfsHttpWebRequest.SendRequestAndGetResponse(HttpWebRequest webRequest, WebException& webException)
   --- End of inner exception stack trace ---
   at Microsoft.TeamFoundation.Client.Channels.TfsHttpWebRequest.ReadResponse(HttpWebResponse webResponse, WebException webException)
   at Microsoft.TeamFoundation.Client.Channels.TfsHttpWebRequest.SendRequest()
   at Microsoft.TeamFoundation.Client.Channels.TfsHttpRequestChannel.Request(TfsMessage message, TimeSpan timeout)
   at Microsoft.TeamFoundation.Client.Channels.TfsHttpClientBase.Invoke(TfsClientOperation operation, Object[] parameters, TimeSpan timeout, Object[]& outputs)
   at Microsoft.TeamFoundation.WorkItemTracking.Proxy.ClientService.GetWorkItem(Int32 workItemId, Int32 revisionId, Int32 minimumRevisionId, Nullable`1 asOfDate, Boolean useMaster, RowSetCollection& workItem, MetadataTableHaveEntry[] metadataHave, String& dbStamp, RowSetCollection& metadata)
   at Microsoft.TeamFoundation.WorkItemTracking.Proxy.WorkItemServer.GetWorkItem(String requestId, Int32 workItemId, Int32 revisionId, Int32 minimumRevisionId, Nullable`1 asOfDate, Boolean useMaster, IWorkItemRowSets& workItem, MetadataTableHaveEntry[] metadataHave, String& dbStamp, IMetadataRowSets& metadata)
   at Microsoft.TeamFoundation.WorkItemTracking.Client.WorkItemStore.LoadWorkItem(Int32 id, Int32 rev, Nullable`1 asof, IWorkItemRowSets& witem)
   at Microsoft.TeamFoundation.WorkItemTracking.Client.WorkItem.EnsureCollections()
   at Microsoft.TeamFoundation.WorkItemTracking.Client.LinkCollection.Populate()
   at Microsoft.TeamFoundation.WorkItemTracking.Client.LinkCollection.get_Count()
   at Microsoft.TeamFoundation.WorkItemTracking.Common.Enumerator`1.MoveNext()
   at MigrationTools.Endpoints.TfsWorkItemConvertor.GetLinkItems(LinkCollection tfsLinks) in D:\a\1\s\src\MigrationTools.Clients.AzureDevops.ObjectModel\Endpoints\TfsWorkItemConvertor.cs:line 92
   at MigrationTools.Endpoints.TfsWorkItemConvertor.MapWorkItemtoWorkItemData(WorkItemData context_wid, WorkItem context_wi, Dictionary`2 fieldsOfRevision) in D:\a\1\s\src\MigrationTools.Clients.AzureDevops.ObjectModel\Endpoints\TfsWorkItemConvertor.cs:line 37
   at MigrationTools.TfsExtensions.ToWorkItemDataList(IList`1 collection) in D:\a\1\s\src\MigrationTools.Clients.AzureDevops.ObjectModel\TfsExtensions.cs:line 163
   at VstsSyncMigrator.Engine.WorkItemMigrationContext.InternalExecute() in D:\a\1\s\src\VstsSyncMigrator.Core\Execution\MigrationContext\WorkItemMigrationContext.cs:line 171
   at MigrationTools._EngineV1.Processors.MigrationProcessorBase.Execute() in D:\a\1\s\src\MigrationTools\_EngineV1\Processors\MigrationProcessorBase.cs:line 47
2024-01-13 11:10:01.282 +05:30 [ERR] WorkItemMigration The Processor MigrationEngine entered the failed state...stopping run

[MrHinsh]

No idea @AjinkyaIG you might need to check with Microsoft...

You can check if you are being rate limited on https://dev.azure.com/org/_settings/usage but you should not get a "service unavailable".