Syncfusion Calendar, Build Failed - No errors, was working before update.

import 'package:syncfusion_flutter_calendar/calendar.dart';

class Calendar extends StatefulWidget {
  const Calendar({
    super.key,
    this.width,
    this.height,
    required this.onAppointmentTapped,
    required this.onCalendarTapped,
  });

  final double? width;
  final double? height;
  final Future<dynamic> Function(Map<String, dynamic>) onAppointmentTapped;
  final Future<dynamic> Function(Map<String, dynamic>) onCalendarTapped;

  @override
  State<Calendar> createState() => _CalendarState();
}

class _CalendarState extends State<Calendar> {
  late MeetingDataSource _flightLogs;
  List<Meeting> _meetings = [];
  List<CalendarResource> _resources = [];
  bool _isLoading = true;
  late CalendarController _calendarController;

  @override
  void initState() {
    super.initState();
    _calendarController = CalendarController();
    _loadTestData();
  }

  @override
  void dispose() {
    _calendarController.dispose();
    super.dispose();
  }

  void _loadTestData() {
    // Create test resources (aircraft)
    _resources = [
      CalendarResource(
        id: '1',
        displayName: 'N12345 - C172',
        color: Colors.blue,
      ),
      CalendarResource(
        id: '2',
        displayName: 'N67890 - PA28',
        color: Colors.green,
      ),
      CalendarResource(
        id: '3',
        displayName: 'N11223 - C152',
        color: Colors.orange,
      ),
      CalendarResource(
        id: '3',
        displayName: 'N11223 - C152',
        color: Colors.orange,
      ),
      CalendarResource(
        id: '3',
        displayName: 'N11223 - C152',
        color: Colors.orange,
      ),
      CalendarResource(
        id: '3',
        displayName: 'Steven',
        color: Colors.orange,
      ),
      CalendarResource(
        id: '3',
        displayName: 'Alex Smith',
        color: Colors.orange,
      ),
      CalendarResource(
        id: '3',
        displayName: 'Meeting Room 1',
        color: Colors.orange,
      ),
    ];

    // Create test meetings (flights)
    final now = DateTime.now();
    _meetings = [
      Meeting(
        'John Smith - Training',
        DateTime(now.year, now.month, now.day, 9, 0),
        DateTime(now.year, now.month, now.day, 11, 0),
        Colors.blue,
        false,
        resourceIds: ['1'],
      ),
      Meeting(
        'Sarah Johnson - Check Ride',
        DateTime(now.year, now.month, now.day, 13, 0),
        DateTime(now.year, now.month, now.day, 15, 0),
        Colors.green,
        false,
        resourceIds: ['2'],
      ),
      Meeting(
        'Mike Davis - Solo',
        DateTime(now.year, now.month, now.day, 10, 0),
        DateTime(now.year, now.month, now.day, 12, 0),
        Colors.orange,
        false,
        resourceIds: ['3'],
      ),
    ];

    setState(() {
      _flightLogs = MeetingDataSource(_meetings);
      _flightLogs.resources = _resources;
      _isLoading = false;
    });
  }

  Future<void> _handleCalendarTapped(CalendarTapDetails details) async {
    if (details.targetElement == CalendarElement.calendarCell) {
      // Handle tap on empty calendar cell
      final Map<String, dynamic> params = {
        'tappedDate': details.date?.millisecondsSinceEpoch,
        'resourceId': details.resource?.id,
        'resourceName': details.resource?.displayName,
      };
      await widget.onCalendarTapped(params);
    } else if (details.targetElement == CalendarElement.appointment) {
      // Handle tap on existing appointment
      final Meeting tappedMeeting = details.appointments?[0] as Meeting;
      final Map<String, dynamic> params = {
        'eventName': tappedMeeting.eventName,
        'startTime': tappedMeeting.from.millisecondsSinceEpoch,
        'endTime': tappedMeeting.to.millisecondsSinceEpoch,
        'resourceIds': tappedMeeting.resourceIds,
        'isAllDay': tappedMeeting.isAllDay,
      };
      await widget.onAppointmentTapped(params);
    }
  }

  @override
  Widget build(BuildContext context) {
    if (_isLoading) {
      return Container(
        width: widget.width,
        height: widget.height,
        child: const Center(
          child: CircularProgressIndicator(),
        ),
      );
    }

    final screenWidth = MediaQuery.of(context).size.width;
    final isMobile = screenWidth < 600;

    return Container(
      width: widget.width,
      height: widget.height,
      child: SfCalendar(
        controller: _calendarController,
        view: CalendarView.timelineDay,
        dataSource: _flightLogs,
        showDatePickerButton: true,
        showTodayButton: true,
        showNavigationArrow: true,
        onTap: _handleCalendarTapped,
        timeSlotViewSettings: TimeSlotViewSettings(
          startHour: 6,
          endHour: 22,
          nonWorkingDays: const <int>[],
          timeFormat: 'HH:mm',
          timeIntervalHeight: -1,
          timeIntervalWidth: isMobile ? 45 : -1,
        ),
        resourceViewSettings: ResourceViewSettings(
          visibleResourceCount: 12,
          showAvatar: false,
          displayNameTextStyle: const TextStyle(
            fontSize: 13,
            fontWeight: FontWeight.w500,
          ),
          size: isMobile ? 80 : 100,
        ),
        viewNavigationMode: ViewNavigationMode.snap,
        allowedViews: const [
          CalendarView.timelineDay,
          CalendarView.timelineWeek,
          CalendarView.timelineWorkWeek,
        ],
      ),
    );
  }
}

class MeetingDataSource extends CalendarDataSource {
  MeetingDataSource(List<Meeting> source) {
    appointments = source;
  }

  @override
  DateTime getStartTime(int index) {
    return appointments![index].from;
  }

  @override
  DateTime getEndTime(int index) {
    return appointments![index].to;
  }

  @override
  String getSubject(int index) {
    return appointments![index].eventName;
  }

  @override
  Color getColor(int index) {
    return appointments![index].background;
  }

  @override
  List<Object>? getResourceIds(int index) {
    return (appointments![index] as Meeting).resourceIds;
  }

  @override
  bool isAllDay(int index) {
    return appointments![index].isAllDay;
  }
}

class Meeting {
  Meeting(
    this.eventName,
    this.from,
    this.to,
    this.background,
    this.isAllDay, {
    this.resourceIds,
  });

  String eventName;
  DateTime from;
  DateTime to;
  Color background;
  bool isAllDay;
  List<Object>? resourceIds;
}