Flutter. The example in the github (growthbook_flutter/example/;lib/main.dart) & your init rules are incompatable. Change either. I am talking about: gb = await GBSDKBuilderApp( hostURL: '....', apiKey: ".....", attributes: userAttr, growthBookTrackingCallBack: (gbExperiment, gbExperimentResult) { // TODO: Use your real analytics tracking system // print("Viewed Experiment"); // print("Experiment Id: " + gbExperiment.key); // print("Variation Id: " + gbExperimentResult.variationId); }, ).initialize(); This thing: growthBookTrackingCallBack: (gbExperiment, gbExperimentResult) ---> either outdated or incompatable

Hi Tom, this SDK is externally maintained. I have cross-posted this query in the Flutter SDK channel here