Since v34.x there is an error when about FAB disposal

[Julien Barach]

Hi,

After updating from v33.x to v34.1.31 I have SpeedDial buttons that don't appear and there is this message in the console :

Error during FAB disposal: Unhandled exception occurred during interop call.

Please see repro : https://blazorplayground.syncfusion.com/VXVnDwLQesTepLes

For now I can't reproduce my case where the SpeedDial is totally missing but I guess resolving this error could fix my issue.

Regards,

Julien

[Priyanka Karthikeyan]

Hi Julien Barach,

Greetings from Syncfusion,

Based on your query, we would like to clarify that, starting with the Volume 2 2026 release(v 34.1.29), the Syncfusion. Blazor overall NuGet package has been unlisted from NuGet.org and will no longer receive updates or new releases. You should migrate from the Syncfusion.Blazor package to the required component-specific Syncfusion Blazor NuGet packages (for example, Syncfusion.Blazor.Buttons, Syncfusion.Blazor.Charts, Syncfusion.Blazor.Schedule, etc.).

 

We have already documented this as a breaking change in the release notes. Kindly refer to the notes below for more information.

 

Release notes: https://blazor.syncfusion.com/documentation/release-notes/34.1.29?type=all#common

 

NuGet Packages List for Blazor Components – Provides details about all available component-specific packages and their dependencies:

• NuGet Packages List for Blazor Components | Syncfusion®

 

You may also find the following getting started guides helpful:

• Getting Started with Blazor Speed Dial in Blazor Web App | Syncfusion

 

Thank you for your understanding. Please let us know if you need any further assistance.

 

Regards,
Priyanka K

[Julien Barach]

Hi,

IMO That's not related to the error printed in the console.

I don't have Syncfusion.Blazor as a dependency.

I see that the last version (v34.1.33) fixes some disposal issues, but on this version the printed error is now :

InvalidOperationException: Unhandled exception occurred during interop call.

Please test on the original repro link.

Regards,

Julien

[LeoLavanya Dhanaraj]

Hi Julien,

We understand that after upgrading from v33.x to v34.1.31, your SpeedDial (FAB) buttons are not rendering as expected, and the browser console displays the error "Error during FAB disposal: Unhandled exception occurred during interop call." You also mentioned that after upgrading to v34.1.33, the error message changed to "InvalidOperationException: Unhandled exception occurred during interop call." Furthermore, we understand that this issue is not related to the Syncfusion.Blazor meta package migration, as your application does not use that package.

From our side, we tested the scenario using the shared reproduction sample and also verified it with the latest available version. During our validation, the SpeedDial component rendered properly, and we were unable to reproduce the reported issue or observe the exception in the console. For your reference, we have included our sample and the corresponding output video.

Sample - https://www.syncfusion.com/downloads/support/directtrac/general/ze/SyncfusionBlazorApp 
Video -  https://www.syncfusion.com/downloads/support/directtrac/general/ze/SpeedDial 

We also noticed your comment regarding disposal-related fixes in recent versions. Yes, we included a fix for the following issue in v34.1.31:

"An exception can escape from Dialog ComponentDispose during JSInterop cleanup and terminate w3wp.exe."

In this scenario, a JSDisconnectedException thrown during JSInterop cleanup was not being caught properly and could escape due to fire-and-forget disposal operations. This fix was included as part of the v34.1.31 release.

Release Notes: https://blazor.syncfusion.com/documentation/release-notes/34.1.31?type=all#dialog

Please review the shared details. If you are still facing the issue, or if we have misunderstood your scenario, could you please provide the following information to help us reproduce the issue and determine whether it is related to the SpeedDial disposal lifecycle?

• A runnable sample that reproduces the issue in your application.
• The hosting model being used (Blazor Server, WebAssembly, or .NET 9/10 Blazor Web App).
• The exact Syncfusion package versions referenced in the project.
• The browser name and version.
• Whether the issue occurs consistently or only during page navigation or component disposal.
• A screenshot or video showing the missing SpeedDial component along with the corresponding browser console error.
• Any custom code executed during component initialization or disposal.

These details will help us investigate the issue further and determine whether the reported exception is related to the SpeedDial component's rendering or disposal behavior.

Regards,
Leo Lavanya