Connector tool no longer connects nodes in SfDiagram after updating

[Aksel Nielsen]

Hello,

After updating from Syncfusion WPF 27.2.2 to 31.2.3, I noticed that the Connector drawing tool stopped working properly.

I created a minimal test project to reproduce the issue. When I click the “Connector” button and try to draw a connector between two nodes, the connector appears, but it does not connect to the nodes (no connection points are established).

In the previous version (27.2.2), the same code worked fine — connectors automatically snapped and connected to nodes.
Below I attach test project. Thanks.

Attachment: DiagramTestApp_9b0ea6e7.7z

[Arun Kumar Sivakumar]

Hi Aksel,

 

Reported issue: Unable to create a connector between two nodes using the Connection Tool.

 

We are able to reproduce the reported issue in the provided sample. Currently, we are validating to find the root cause of the reported issue. We will update you with more details on or before November 03, 2025.

 

Regards,

Arun Kumar S

[Arun Kumar Sivakumar]

Hi Aksel,

Reported issue:  Unable to create a connector between two nodes using the Connection Tool.

We have confirmed that the reported issue is a bug from our end. We have logged a bug report for the reported issue. We will fix this issue and include the fix in our upcoming Weekly NuGet release, which will be planned for November 18, 2025. For more details about the bug, please follow the below feedback link.

Feedback link: Unable to create a connector between two nodes using the Connection Tool in WPF | Feedback Portal

Disclaimer: “Inclusion of this solution in the weekly release may change due to other factors, including but not limited to QA checks and work reprioritization

Regards,

Arun Kumar S

[Arun Kumar Sivakumar]

Hi Aksel,

 

Reported issue:  Unable to create a connector between two nodes using the Connection Tool.

 

We are glad to announce that our Weekly NuGet v331.2.12 is rolled out and is available for download under the following link. We have fixed the reported issue and included the fix in it.

 

NuGet Version: 31.2.12

NuGet link: NuGet Gallery | Syncfusion.SfDiagram.WPF 31.2.12

 

We thank you for your support and appreciate your patience in waiting for this release. Please get in touch with us if you require any further assistance.

 

Regards,

Arun Kumar S

[Aksel Nielsen]

Good afternoon.

Thank you for the update. I have upgraded to latest SfDiagram.WPF and I can confirm that drawing connectors between nodes without ports now works correctly. 

However, I would like to report that we still observe the same issue in diagrams where NodeViewModel uses NodePortViewModel:

• When I click the “Connector” tool
• And try to draw a connector between two ports
• The connector does not appear
• And it does not connect to the node ports
  

[Aksel Nielsen]

Good afternoon.

Thank you for the update. I have upgraded to latest SfDiagram.WPF and I can confirm that drawing connectors between nodes without ports now works correctly. 

However, I would like to report that we still observe the same issue in diagrams where NodeViewModel uses NodePortViewModel:

• When I click the “Connector” tool
• And try to draw a connector between two ports
• The connector does not appear
• And it does not connect to the node ports
  

[Arun Kumar Sivakumar]

Hi Aksel,

 

Reported issue: Unable to create a connector between two ports using the Connection Tool.

 

We tested the reported issue using the latest version of the NuGet packages and were unable to reproduce it. Please verify the NuGet package versions in your project and update them to the latest version if they are not already updated. 

 

If the issue persists, kindly reproduce it using the provided sample and share the updated sample with us. This will help us identify the root cause and provide an accurate solution.

 

For your reference, we have included the tested sample and a video demonstrating the functionality.

 

Regards,

Arun Kumar S

Attachment: Sample_and_Video_8975b099.zip

[Aksel Nielsen]

Hello again, I attempted to reproduce the above-mentioned issue. After adding two elements from the stencil, when selecting the Connector tool, the target port is not activated, and the connector is not rendered.

Attachment: DiagramTestApp2_5d2659dd.7z

[Arun Kumar Sivakumar]

Hi Aksel,

 

Reported issue: Unable to create a connector between two ports using the Connection Tool.

 

We have validated the provided sample and observed that you used logic circuit diagram shapes. Please note that certain connection restrictions apply to these shapes. For example, shapes under the Input Controls category cannot accept incoming connections, and shapes under the Output Controls category cannot accept outgoing connections. However, you can draw a connector from an Input Controls shape and connect it to any shape outside the Input Controls category.

 

Could you share which two elements you are attempting to add and connect within the diagram? Alternatively, kindly provide a video demonstration of the steps you performed. This will enable us to assist you with a better solution.

 

Regards,

Arun Kumar S

[Aksel Nielsen]

I have provided two videos demonstrating the behavior in different versions of the Syncfusion controls (version 30.x and version 32.x).

As you can see in the videos, in the latest version of the controls it is not possible to connect two shapes using the Connection Tool, while in the older version everything works correctly. The example is the same one that I shared earlier.

You can reproduce the issue by using the same sample and testing it with the older version of the controls.

Please let me know if you need any additional information from my side.

Attachment: videos_47b5a936.7z

[Aksel Nielsen]

I have provided two videos demonstrating the behavior in different versions of the Syncfusion controls (version 30.x and version 32.x).

As you can see in the videos, in the latest version of the controls it is not possible to connect two shapes using the Connection Tool, while in the older version everything works correctly. The example is the same one that I shared earlier.

You can reproduce the issue by using the same sample and testing it with the older version of the controls.

Please let me know if you need any additional information from my side.

[Arun Kumar Sivakumar]

Hi Aksel,

 

Reported issue: Unable to create a connector between two nodes using the Connection Tool in the latest version NuGet.

 

We have tested your reported issue using the old and new version NuGet packages that you have mentioned in your video using the simple sample. However, we are unable to reproduce the reported issue using the simple sample. We have provided the tested video and sample for your reference. Kindly reproduce the reported issue in the provided sample and share it with us or provide the issue replicated sample. This will be helpful for us to provide the solution for your reported issue.

 

Regards,

Arun Kumar S

Attachment: Sample_and_video_40d8c3d8.zip