diff --git a/lib/models/dhcp.dart b/lib/models/dhcp.dart
index 7bba2ca..aaf4a42 100644
--- a/lib/models/dhcp.dart
+++ b/lib/models/dhcp.dart
@@ -55,8 +55,8 @@ String dhcpStatusToJson(DhcpStatus data) => json.encode(data.toJson());
 
 class DhcpStatus {
   String? interfaceName;
-  IpVersion v4;
-  IpVersion v6;
+  IpVersion? v4;
+  IpVersion? v6;
   List<Lease> leases;
   List<Lease> staticLeases;
   bool enabled;
@@ -81,8 +81,8 @@ class DhcpStatus {
 
   Map<String, dynamic> toJson() => {
     "interface_name": interfaceName,
-    "v4": v4.toJson(),
-    "v6": v6.toJson(),
+    "v4": v4 != null ? v4!.toJson() : null,
+    "v6": v6 != null ? v6!.toJson() : null,
     "leases": List<Lease>.from(leases.map((x) => x)),
     "static_leases": List<Lease>.from(staticLeases.map((x) => x)),
     "enabled": enabled,
diff --git a/lib/models/dns_info.dart b/lib/models/dns_info.dart
index 528ca5b..138efa3 100644
--- a/lib/models/dns_info.dart
+++ b/lib/models/dns_info.dart
@@ -10,8 +10,8 @@ class DnsInfo {
   bool disableIpv6;
   String? upstreamMode;
   int? cacheSize;
-  int cacheTtlMin;
-  int cacheTtlMax;
+  int? cacheTtlMin;
+  int? cacheTtlMax;
   bool cacheOptimistic;
   bool resolveClients;
   bool usePrivatePtrResolvers;
diff --git a/lib/models/encryption.dart b/lib/models/encryption.dart
index 3e2e230..8f8a3a0 100644
--- a/lib/models/encryption.dart
+++ b/lib/models/encryption.dart
@@ -32,7 +32,7 @@ class EncryptionData {
   final int? portDnsOverTls;
   final int? portDnsOverQuic;
   final int? portDnscrypt;
-  final String dnscryptConfigFile;
+  final String? dnscryptConfigFile;
   final bool allowUnencryptedDoh;
   final String certificateChain;
   final String privateKey;
diff --git a/lib/screens/settings/dhcp/dhcp.dart b/lib/screens/settings/dhcp/dhcp.dart
index 402a063..a93a338 100644
--- a/lib/screens/settings/dhcp/dhcp.dart
+++ b/lib/screens/settings/dhcp/dhcp.dart
@@ -61,11 +61,13 @@ class _DhcpScreenState extends State<DhcpScreen> {
           if (dhcpProvider.dhcp!.dhcpStatus.interfaceName != null && dhcpProvider.dhcp!.dhcpStatus.interfaceName != '') {
             try {selectedInterface = dhcpProvider.dhcp!.networkInterfaces.firstWhere((iface) => iface.name == dhcpProvider.dhcp!.dhcpStatus.interfaceName);} catch (_) {}
             enabled = dhcpProvider.dhcp!.dhcpStatus.enabled;
-            ipv4StartRangeController.text = dhcpProvider.dhcp!.dhcpStatus.v4.rangeStart;
-            ipv4EndRangeController.text = dhcpProvider.dhcp!.dhcpStatus.v4.rangeEnd ?? '';
-            ipv4SubnetMaskController.text = dhcpProvider.dhcp!.dhcpStatus.v4.subnetMask ?? '';
-            ipv4GatewayController.text = dhcpProvider.dhcp!.dhcpStatus.v4.gatewayIp ?? '';
-            ipv4LeaseTimeController.text = dhcpProvider.dhcp!.dhcpStatus.v4.leaseDuration.toString();
+            if (dhcpProvider.dhcp!.dhcpStatus.v4 != null) {
+              ipv4StartRangeController.text = dhcpProvider.dhcp!.dhcpStatus.v4!.rangeStart;
+              ipv4EndRangeController.text = dhcpProvider.dhcp!.dhcpStatus.v4!.rangeEnd ?? '';
+              ipv4SubnetMaskController.text = dhcpProvider.dhcp!.dhcpStatus.v4!.subnetMask ?? '';
+              ipv4GatewayController.text = dhcpProvider.dhcp!.dhcpStatus.v4!.gatewayIp ?? '';
+              ipv4LeaseTimeController.text = dhcpProvider.dhcp!.dhcpStatus.v4!.leaseDuration.toString();
+            }
           }
         });
       }
diff --git a/lib/screens/settings/general_settings.dart b/lib/screens/settings/general_settings.dart
index e68aae3..1f73784 100644
--- a/lib/screens/settings/general_settings.dart
+++ b/lib/screens/settings/general_settings.dart
@@ -63,6 +63,7 @@ class _GeneralSettingsState extends State<GeneralSettings> {
         isBeta: appConfigProvider.getAppInfo!.version.contains('beta'),
       );
 
+      if (!mounted) return;
       if (res != null) {
         setState(() => appUpdatesStatus = AppUpdatesStatus.available);
       }
diff --git a/lib/widgets/combined_line_chart.dart b/lib/widgets/combined_line_chart.dart
index 14d6d3e..3b82f1f 100644
--- a/lib/widgets/combined_line_chart.dart
+++ b/lib/widgets/combined_line_chart.dart
@@ -26,6 +26,8 @@ class CustomCombinedLineChart extends StatelessWidget {
     String chartDate(DateTime date) {
       String twoDigits(int number) => number.toString().padLeft(2, '0');
 
+      String shortMonth(String month) => month.length > 3 ? month.substring(0, 3) : month;
+
       String getMonth(int month) {
         final List<String> months = [
           AppLocalizations.of(context)!.january,
@@ -45,10 +47,10 @@ class CustomCombinedLineChart extends StatelessWidget {
       }
       
       if (daysInterval == true) {
-        return "${date.day} ${getMonth(date.month).substring(0, 3)}";
+        return "${date.day} ${shortMonth(getMonth(date.month))}";
       }
       else {
-        return "${date.day} ${getMonth(date.month).substring(0, 3)} ${twoDigits(date.hour)}:00";
+        return "${date.day} ${shortMonth(getMonth(date.month))} ${twoDigits(date.hour)}:00";
       }
     }
 
diff --git a/lib/widgets/line_chart.dart b/lib/widgets/line_chart.dart
index 92814b1..c94ec5d 100644
--- a/lib/widgets/line_chart.dart
+++ b/lib/widgets/line_chart.dart
@@ -24,6 +24,8 @@ class CustomLineChart extends StatelessWidget {
   String chartDate(DateTime date) {
     String twoDigits(int number) => number.toString().padLeft(2, '0');
 
+    String shortMonth(String month) => month.length > 3 ? month.substring(0, 3) : month;
+
     String getMonth(int month) {
       final List<String> months = [
         AppLocalizations.of(context)!.january,
@@ -44,10 +46,10 @@ class CustomLineChart extends StatelessWidget {
     }
   
     if (daysInterval == true) {
-      return "${date.day} ${getMonth(date.month).substring(0, 3)}";
+      return "${date.day} ${shortMonth(getMonth(date.month))}";
     }
     else {
-      return "${date.day} ${getMonth(date.month).substring(0, 3)} ${twoDigits(date.hour)}:00";
+      return "${date.day} ${shortMonth(getMonth(date.month))} ${twoDigits(date.hour)}:00";
     }
   }