Custom Action Saving Issue: "Failed to process parameters" and Function Disappearing

[vijayanirmalamadhu-code]

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

Hi FlutterFlow Support Team,

I am facing a persistent bug in my project regarding Custom Actions. Even with a brand-new Custom Action containing a single simple parameter (e.g., a single String parameter like proprietorName), the editor behaves strangely:

The code validates successfully with a green checkmark.

However, when I click Save, a pop-up appears saying: "Failed to process parameters. Are you sure you want to save?"

If I proceed, the custom action completely disappears from the function list and fails to save entirely.

I have tried clearing the browser cache, hard refreshing, and recreating the action multiple times, but the parameter processing mechanism seems to be broken for custom actions in my project.

Could you please check why the custom action parameters are failing to process despite valid syntax and correct data types?

Thanks and regards,
Darla Madhu

Expected Behavior

When creating a custom action with valid syntax and properly defined parameters, clicking "Save" should successfully compile the action, store it in the project's custom action list without any warning pop-ups like "Failed to process parameters", and allow it to be used seamlessly in the app logic.

Steps to Reproduce

1. Go to Custom Actions in FlutterFlow and click on Create New Action.

2. Keep the default action name (newCustomAction).

3. Add a single parameter (e.g., proprietorName with type String).

4. Paste a valid Dart code block containing that parameter.

5. Click on Validate (it shows a green checkmark successfully).

6. Click on Save.

Result: A pop-ion error appears saying "Failed to process parameters. Are you sure you want to save?", and upon saving, the action completely disappears and fails to save in the list.

Reproducible from Blank

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

Bug Report Code (Required)

IT4kksrl34x2tbxG17X1bcBshiIWC204TL07ttYbZxUjIuPtBJh/fMneTxNvXsfkSmlhHFmgrHsFpMr9ufLxOsI4PTOcR5x5/qtQQw/NWXq8RJi2OpOaPn9RMNFXGUye5omr2yQkKrBiLFYg7GamAenKSXXDJ5u/Zwh9f6PHaOI=

Visual documentation

Issue Description:
Even when creating a brand-new Custom Action with a single parameter and valid syntax, clicking "Save" triggers the error: "Failed to process parameters. Are you sure you want to save?" Upon saving, the custom action completely disappears from the list. Parameter processing in the custom action editor seems completely broken for this project.

Environment

- FlutterFlow version: Latest
- Platform:Web
- Browser name and version: Chrome, Latest Version
- Operating system and version affected: Windows 10

Additional Information

No response

[Alezanello]

Hello!

I wasn’t able to replicate this behavior in a new, blank project. Could you please share a screen recording showing the issue and the steps leading up to it? This will help me investigate further.

Screen Recording 2026-08-18 at 8.24.51 AM.mov