Persistent Crashes (FlutterError: Null) - Data Not Loaded/Checked Correctly

Hello FlutterFlow Community,

I'm consistently running into a common issue that causes my app to crash with a Fatal Exception: FlutterError. It seems to be related to trying to access data that hasn't finished loading yet, or is null, particularly within ListViews and FutureBuilder contexts.

Here's a typical stack trace I'm seeing (example from a recent crash, but patterns are similar):

Fatal Exception: FlutterError
0   ???                                 0x0 _ProfilWidgetState.build.<fn>.<fn> + 158 (profil_widget.dart:158)
1   ???                                 0x0 _ProfilWidgetState.build.<fn> + 164 (profil_widget.dart:164)
2   ???                                 0x0 _FutureBuilderState.build + 626 (async.dart:626)
... (rest of stack trace)

And previously, I had crashes like this within a ListView.separated itemBuilder:

claimrewardsUsersRow!.supersecret.toList(), // Line 405 from claimrewards_widget.dart

The Problem (as I understand it):

It appears that the generated FlutterFlow code is attempting to access properties or call methods (e.g., .supersecret, .toList()) on variables that are null. This typically happens when:

1. Backend Queries haven't completed loading yet.

2. A specific document/data point doesn't exist (so the query returns null).

FlutterFlow often generates FutureBuilders implicitly for backend queries, and if snapshot.data is null (or the query is still loading) and not properly handled, it leads to these crashes when ! (null-check operator) is used on null values.

My Question:

What is the simplest and most robust FlutterFlow-native way to prevent these types of crashes when dealing with asynchronous data loading and potentially null values from backend queries?

I've been trying to use Conditional Builders with "Is Set" and "Is Loaded" conditions. For example:

• Wrapping a ListView with a Conditional Builder checking if the main Document Query (claimrewardsUsersRow in my case) "Is Set".

• Wrapping individual list items or parts of the UI with a Conditional Builder checking if specific row data (listViewSurveyUsersSubmitsRow) "Is Set".

Any guidance, examples, or pointers to FlutterFlow tutorials/documentation that specifically address this common "null data crash" scenario would be greatly appreciated! I'm trying to make my app as stable as possible.

Thanks in advance for your help!