Could not find the correct Provider - Flutter

According to the latest version of the Provider package, the builder() method of ChangeNotifierProvider was changed to create(). So editing Esen Mehmet's version, this will work instead:

ChangeNotifierProvider(
      create: (context) => MySchedule(),  //change builder to create
      child: Consumer<MySchedule>(
              builder: (context, provider, child) => Scaffold(....,

You need a builder bridge between ChangeNotifierProvider and Scaffold.

Provider package already has it's own builder called Consumer, you can use it like:

ChangeNotifierProvider<MySchedule>(
          create: (context) => MySchedule(),
          child: Consumer<MySchedule>(
                  builder: (context, provider, child) => Scaffold(....,

Check this link: https://pub.dev/packages/provider#reading-a-value

edit: builder is now create.