Web (WASM enabled): Upload Media with “Include Blur Hash” fails to generate BlurHash (Null check error)

[kicsijohn]

Can we access your project?

• I give permission for members of the FlutterFlow team to access and test my project for the sole purpose of investigating this issue.

Current Behavior

When WASM is enabled for Web deployment, using Upload Media with Include Blur Hash turned on fails during upload and does not generate BlurHash on the web app.
Observed on Web app (not tested on other platforms).

Observed error (console / runtime):

Null check operator used on a null value

Stack trace points to BlurHash generation / image decoding, e.g.:

PngDecoder.decode

decodeImage

_generateBlurHash

compute (web isolate)

Expected Behavior

If an image is uploaded and Include Blur Hash is enabled, FlutterFlow should successfully generate and return/store the BlurHash value for the uploaded image (including when WASM is turned on for Web).

Steps to Reproduce

• Open any FlutterFlow project.
• Add a Button to a page.
• Add an Action → Upload Media to the button.
• Enable Include Blur Hash toggle in the Upload Media action.
• Go to Web Deployment settings/page.
• Turn WASM ON.
• Run the web app (locally or deployed) and click the button to upload an image.
• Observe that BlurHash generation fails and the runtime error appears.

Reproducible from Blank

• The steps to reproduce above start from a blank project.

Bug Report Code (Required)

ITEelsn1z4pNj7xD0LXyKcZsmQMxQUB+bZ0vlO1FGEwbJbKuO7AEP87UaXdYXNe+dwtAGWGboF8ewcHFhvDhOPA4FyWAfqF607tqUTvidziWbpiMC5C8W0dCRNpVC3aM55272wlRCNdeW3Ah6k+Hcq3qNleeY8aSfxBlZ7vfcPo=

Visual documentation

https://share.cleanshot.com/lGVw2ZG9

Environment

- FlutterFlow version: FlutterFlow v6.4.81 released December 16, 2025
Flutter version is 3.32.4

Platform: Web
Condition: Only reproducible when WASM is enabled
Not tested elsewhere (Android/iOS/Desktop unknown)

Additional Information

No response

[Juansarmi]

Hi!
Thank you for your report. As you can see on the platform, the “Use WASM” option is still in beta, so issues like this may occur.

For now, you may continue developing your app by disabling BlurHash when uploading your images or by disabling Use WASM.

In the meantime, I will share this with the engineering team and will let you know as soon as I have any updates.

Best regards