diff --git a/Pilz.Updating.Client/Pilz.Updating.Client.csproj b/Pilz.Updating.Client/Pilz.Updating.Client.csproj
index b729892..13f26b4 100644
--- a/Pilz.Updating.Client/Pilz.Updating.Client.csproj
+++ b/Pilz.Updating.Client/Pilz.Updating.Client.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFrameworks>net8.0</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <PropertyGroup>
diff --git a/Pilz.Updating.Client/UpdateClient.cs b/Pilz.Updating.Client/UpdateClient.cs
index 7b8defc..cf1c607 100644
--- a/Pilz.Updating.Client/UpdateClient.cs
+++ b/Pilz.Updating.Client/UpdateClient.cs
@@ -6,7 +6,7 @@ public class UpdateClient(string updateUrl, AppVersion currentVersion, Channels
 {
     // E v e n t s
 
-    public event UpdateClientStatusChangedEventHandler OnStatusChanged;
+    public event UpdateClientStatusChangedEventHandler? OnStatusChanged;
 
     // F i e l d s
 
@@ -18,8 +18,8 @@ public class UpdateClient(string updateUrl, AppVersion currentVersion, Channels
     public string UpdateUrl { get; private set; } = updateUrl;
     public AppVersion CurrentVersion { get; private set; } = currentVersion;
     public Channels MinimumChannel { get; private set; } = (Channels)Math.Max((int)minimumChannel, (int)currentVersion.Channel);
-    public UpdateInfo UpdateInfo { get; private set; } = null;
-    public UpdatePackageInfo UpdatePackageInfo { get; private set; } = null;
+    public UpdateInfo? UpdateInfo { get; private set; }
+    public UpdatePackageInfo? UpdatePackageInfo { get; private set; }
     public string HostApplicationPath { get; set; } = string.Empty;
     public string ApplicationName { get; set; } = string.Empty;
     public bool InstallAsAdmin { get; set; } = false;
@@ -51,7 +51,7 @@ public class UpdateClient(string updateUrl, AppVersion currentVersion, Channels
     {
         var latestVersion = await CheckForUpdate();
 
-        if (HasUpdates)
+        if (HasUpdates && latestVersion is not null)
             await UpdateInteractive(latestVersion);
     }
 
@@ -63,14 +63,14 @@ public class UpdateClient(string updateUrl, AppVersion currentVersion, Channels
 
     // F e a t u r e s
 
-    public async Task<UpdateInfo> GetUpdateInfo()
+    public async Task<UpdateInfo?> GetUpdateInfo()
     {
         string str = await WebClient.GetStringAsync(UpdateUrl);
         var info = UpdateInfo.Parse(str);
         return info;
     }
 
-    private async Task<UpdatePackageInfo> CheckForUpdate()
+    private async Task<UpdatePackageInfo?> CheckForUpdate()
     {
         RaiseStatusChanged(UpdateStatus.Searching, UpdateStatusEvent.PreEvent);
 
@@ -82,29 +82,26 @@ public class UpdateClient(string updateUrl, AppVersion currentVersion, Channels
         return CheckForUpdate(UpdateInfo);
     }
 
-    private UpdatePackageInfo CheckForUpdate(UpdateInfo updateInfo)
+    private UpdatePackageInfo? CheckForUpdate(UpdateInfo updateInfo)
     {
-        UpdatePackageInfo foundPkgInfo = null;
         var latestVersion = CurrentVersion;
 
         foreach (UpdatePackageInfo pkgInfo in updateInfo.Packages)
         {
             if (pkgInfo.Version.Channel <= MinimumChannel && pkgInfo.Version > latestVersion)
             {
-                foundPkgInfo = pkgInfo;
+                UpdatePackageInfo = pkgInfo;
                 latestVersion = pkgInfo.Version;
             }
         }
 
-        UpdatePackageInfo = foundPkgInfo;
-
         if (!RaiseStatusChanged(UpdateStatus.Searching, UpdateStatusEvent.PostEvent, true))
         {
             UpdatePackageInfo = null;
             return null;
         }
 
-        return foundPkgInfo;
+        return UpdatePackageInfo;
     }
 
     public async Task<bool> DownloadPackageAsync(UpdatePackageInfo package)
@@ -171,7 +168,7 @@ public class UpdateClient(string updateUrl, AppVersion currentVersion, Channels
         RaiseStatusChanged(UpdateStatus.Copying, UpdateStatusEvent.PreEvent);
         var dataPathDir = new DirectoryInfo(dataPath);
         var destDir = new DirectoryInfo(HostApplicationPath);
-        General.CopyFiles(dataPathDir, destDir);
+        Utils.CopyFiles(dataPathDir, destDir);
         RaiseStatusChanged(UpdateStatus.Copying, UpdateStatusEvent.PostEvent);
 
         // Delete Package
diff --git a/Pilz.Updating/Pilz.Updating.csproj b/Pilz.Updating/Pilz.Updating.csproj
index 7100d4d..0a0fc35 100644
--- a/Pilz.Updating/Pilz.Updating.csproj
+++ b/Pilz.Updating/Pilz.Updating.csproj
@@ -3,7 +3,7 @@
   <PropertyGroup>
     <TargetFrameworks>net8.0</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>annotations</Nullable>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <PropertyGroup>
diff --git a/Pilz.Updating/UpdateInfo.cs b/Pilz.Updating/UpdateInfo.cs
index a4ebef1..90534a1 100644
--- a/Pilz.Updating/UpdateInfo.cs
+++ b/Pilz.Updating/UpdateInfo.cs
@@ -6,7 +6,7 @@ public class UpdateInfo
 {
     public List<UpdatePackageInfo> Packages { get; set; } = [];
 
-    public static UpdateInfo Parse(string str)
+    public static UpdateInfo? Parse(string str)
     {
         return JsonConvert.DeserializeObject<UpdateInfo>(str);
     }
diff --git a/Pilz.Updating/UpdateNotes.cs b/Pilz.Updating/UpdateNotes.cs
index f698361..f92aa60 100644
--- a/Pilz.Updating/UpdateNotes.cs
+++ b/Pilz.Updating/UpdateNotes.cs
@@ -7,9 +7,9 @@ public class UpdateNotes
     [JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
     public UpdateNotesMode Mode { get; set; } = UpdateNotesMode.None;
 
-    public string ExternalUrl { get; set; }
+    public string? ExternalUrl { get; set; }
 
-    public string ContentUrl { get; set; }
+    public string? ContentUrl { get; set; }
 
     [JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
     public UpdateNotesContentType ContentType { get; set; } = UpdateNotesContentType.PlainText;
diff --git a/Pilz.Updating/UpdatePackageInfo.cs b/Pilz.Updating/UpdatePackageInfo.cs
index 2af4147..80119e3 100644
--- a/Pilz.Updating/UpdatePackageInfo.cs
+++ b/Pilz.Updating/UpdatePackageInfo.cs
@@ -1,9 +1,9 @@
 namespace Pilz.Updating;
 
-public class UpdatePackageInfo
+public class UpdatePackageInfo(AppVersion version, string packagelink)
 {
-    public string Name { get; set; }
-    public AppVersion Version { get; set; }
+    public string? Name { get; set; }
+    public AppVersion Version { get; set; } = version;
     public UpdateNotes Notes { get; } = new();
-    public string Packagelink { get; set; }
+    public string Packagelink { get; set; } = packagelink;
 }
\ No newline at end of file