.Net: Bug: Wrong input: Vector dimension error: expected dim: 3072, got 0 with qdrant server 1.17.0

[TsengSR]

Describe the bug
Getting GprcExceptions with latest qdrant version 1.17 due to changes in grpc api

	5 unhandled exceptions: 02/21/2026 00:27:07 +00:00: Microsoft.Extensions.VectorData.VectorStoreException: Call to vector store failed.
---> Grpc.Core.RpcException: Status(StatusCode="InvalidArgument", Detail="Wrong input: Vector dimension error: expected dim: 3072, got 0")
at Qdrant.Client.QdrantClient.UpsertAsync(UpsertPoints request, CancellationToken cancellationToken)
at Qdrant.Client.QdrantClient.UpsertAsync(String collectionName, IReadOnlyList`1 points, Filter updateFilter, Boolean wait, Nullable`1 ordering, ShardKeySelector shardKeySelector, CancellationToken cancellationToken)
at Microsoft.Extensions.VectorData.VectorStoreErrorHandler.RunOperationAsync[TResult,TException](VectorStoreCollectionMetadata metadata, String operationName, Func`1 operation)
--- End of inner exception stack trace ---
at Microsoft.Extensions.VectorData.VectorStoreErrorHandler.RunOperationAsync[TResult,TException](VectorStoreCollectionMetadata metadata, String operationName, Func`1 operation)
at Microsoft.SemanticKernel.Connectors.Qdrant.QdrantCollection`2.UpsertAsync(IEnumerable`1 records, CancellationToken cancellationToken)
at Microsoft.SemanticKernel.Connectors.Qdrant.QdrantCollection`2.UpsertAsync(TRecord record, CancellationToken cancellationToken)
at MyProjectName.Handles.MetadataHandler.Handle(MetadataUpdate`1 command) in /home/vsts/work/1/s/src/MyProjectName/Handles/MetadataHandler.cs:line 70
at Rebus.Pipeline.Receive.HandlerInvoker`1.Invoke()
at Rebus.Diagnostics.Incoming.HandlerInvokerWrapper.Invoke()
at Rebus.Pipeline.Receive.DispatchIncomingMessageStep.Process(IncomingStepContext context, Func`1 next)
at Rebus.Sagas.LoadSagaDataStep.Process(IncomingStepContext context, Func`1 next)
at Rebus.Pipeline.Receive.ActivateHandlersStep.Process(IncomingStepContext context, Func`1 next)
at Rebus.Pipeline.Receive.HandleRoutingSlipsStep.Process(IncomingStepContext context, Func`1 next)
at Rebus.Pipeline.Receive.DeserializeIncomingMessageStep.Process(IncomingStepContext context, Func`1 next)
at Rebus.DataBus.ClaimCheck.HydrateIncomingMessageStep.Process(IncomingStepContext context, Func`1 next)
at Rebus.Pipeline.Receive.HandleDeferredMessagesStep.Process(IncomingStepContext context, Func`1 next)
at Rebus.Retry.Simple.DefaultRetryStep.Process(IncomingStepContext context, Func`1 next)

To Reproduce
Steps to reproduce the behavior:

1. Install Qdrant 1.16.3 (via Docker or Kubernetes)

2. Setup example project

       VectorStoreCollection<ulong, VectorModels.Project> projects = await GetProjectsCollection();
       VectorModels.Project? project = await projects.GetAsync((ulong)projectId, new()
       {
           IncludeVectors = true // This worked before
       });
       if (project is null)
       {
          // log not found
           return;
       }
       await projects.UpsertAsync(project);

3. It will work

4. Upgrade to Qdrant 1.17.0

5. Run again. Exception will be thrown.

6. Downgrading to Qdrant 1.16.3 doesn't make it work either (beats me)

Expected behavior
Vectors to be loaded and metadata (which are not affected by vectors, as they are merely used for filtering and additional information) to be fetched correctly and sent with the upsert

Platform

• Language: C#
• Source: NuGet, Version 1.72 with the corresponding Qdrant connector
• AI model: No model required for this (updating metadata only)
• IDE: Visual Studio 2026
• OS: Developmnet Windows, Application runs in Docker on .NET 10 and k8s

Additional context

• Downgrading to Qdrant 1.16.3 doesn't unlock, error still persists
• Upgrading transient Dependency of Qdrant.Client to latest version 1.17.0 did not fix it either.

[TsengSR]

Any news on this one? Its somewhat blocking parts of my project right now, where metadata is updated only

[TsengSR]

I had a second look at it, since I had flu the whole last week after posting the issue and found the failing place and validated it with my project that it now correctly returns the embeddings and made a minimal PR to fix it. Works with currently referenced 1.15.1 Qdrant.Client library as well as the new 1.16+ (1.17 deprecated the .Data property of VectorOutput in favor for separate properties for the different vector types (dense, sparse and multi-dense)

[TsengSR]

@roji @westey-m
Any chance #13638 could make it in the next release? It's a minimal change that fixes the incompatibility with qdrant server 1.17+