After updating to 30.1.39, the Blazor File Manager no longer shows a preview

[Thinh]

Dear Syncfusion

It seem like the path for previewing is incorrect somewhere, even in your example:

[LeoLavanya Dhanaraj]

Hi Thinh,

Greetings from Syncfusion support.

With the shared details, we have validated and considered the reported scenarios of “Image preview is not loaded in the FileManager flat data support” as a bug on our end. The fix for this issue will be included in the weekly patch release which is scheduled for July 29, 2025.

You can track the status of the fix through the following link.

Feedback: https://www.syncfusion.com/feedback/68891/image-preview-is-not-loaded-in-the-filemanager-flat-data-support

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

Regards,

Leo Lavanya Dhanaraj

[LeoLavanya Dhanaraj]

Hi Thinh,

We were unable to include the fix for the issue(“Image preview is not loaded in the FileManager flat data support”) as promised in the weekly patch release scheduled to be published on 07/29/2025. Currently, we are working on the fix with high priority, and it will be included in the next weekly release (08/05/2025) without any further delay.

We apologize for any inconvenience this may have caused and appreciate your understanding.

[LeoLavanya Dhanaraj]

Hi Thinh,

Thanks for your patience.

We are glad to announce that our Essential Studio 2025 Volume 2 SP release v30.2.4 is rolled out and is available for download under the following link.

https://www.syncfusion.com/forums/197303/essential-studio-2025-volume-2-service-pack-release-v30-2-4-is-available-for-download

The issue where “Image preview is not loaded in the FileManager flat data support” has been resolved in that release itself. To access this fix, we suggest you update the package to the latest version 30.2.4 and we include the demo for your reference.

Demo :  https://blazor.syncfusion.com/demos/file-manager/flat-data?theme=fluent2

Feedback : https://www.syncfusion.com/feedback/68891/image-preview-is-not-loaded-in-the-filemanager-flat-data-support

Release Note : We will refresh the release notes at the earliest.

Root cause : When using the BeforeImageLoad event in the FileManager component with flat data, the image preview fails to load because of an incorrect approach in handling FileStream and custom URL inputs in the GetSrcLink method. The previous logic didn't properly evaluate which source to use when both options were available, particularly when a custom URL was provided through the BeforeImageLoad event. This caused the component to either ignore valid custom URLs or attempt to process non-existent FileStream objects, leading to failed image previews.

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

Regards,

Leo Lavanya Dhanaraj

[verdant switch]

glad to announce that our Essential Studio 2025 Volume 2 SP release v30.2.4 is rolled out and is available for download under the following link.

https://blazor.syncfusion.com/demos/file-manager/flat-data?theme=fluent2  gorilla tag

[Sivakumar ShunmugaSundaram]

Hi verdant switch,

Thank you for your post and interest in our Essential Studio releases. It looks like you're referencing the resolution we shared back in August 2025 for the Blazor File Manager preview issue. 

If you're encountering any issues with previews in flat data support or need help upgrading, could you share more details about your setup (e.g., version, custom configurations, or error logs)? Our demo is a great starting point: Blazor File Manager Example | Flat Data | Syncfusion

Regards,

Sivakumar S