update: more error handling

app/lib/data_classes.dart

@@ -23,7 +23,9 @@ class Measurement {
     try {
       return Measurement(
         measurementID: json['MeasurementID'] ?? 0,
-        timeMeasured: DateTime.parse(json['TimeMeasured']),
+        timeMeasured: json['TimeMeasured'] != null
+            ? DateTime.parse(json['TimeMeasured'])
+            : DateTime(0),
         sensor: Sensor.fromJson(json['Sensor']),
         bodyOfWater: json['BodyOfWater'] != null ? json['BodyOfWater'].toString() : 'nil',
         center: LatLng(
@@ -148,6 +150,14 @@ class Sensor {
 
   factory Sensor.fromJson(Map<String, dynamic> json) {
     try {
+      if (json == null) {
+        return Sensor(
+          sensorID: -1,
+          sensorType: 'Weather data only',
+          active: false
+        );
+      }
+
       return Sensor(
         sensorID: json['SensorID'] ?? 0,
         sensorType: json['SensorType'] ?? 'nil',

server/map_handler/get_measurements.py

 import json
+from datetime import datetime
 
 from server.consts import LAKE_RELATIONS_PATH
 from server.ModelFromNVE.icemodellingscripts.getIceThicknessLakes import get_raw_dates, ice_prognosis_raw_data
@@ -74,7 +75,7 @@ def get_measurements(self, cursor, lake_name):
         remaining_sub_divs = fillRemainingSubdivisions(lake_name, sub_div_ids)
         measurement_data[-1] = {
             'MeasurementID': -1,
-            'TimeMeasured': None,
+            'TimeMeasured': datetime.now(),
             'CenterLat': None,
             'CenterLon': None,
             'Sensor': None,