diff --git a/TriasDev.Templify.Gui/App.axaml.cs b/TriasDev.Templify.Gui/App.axaml.cs
index 9ff3835..c9a1fe6 100644
--- a/TriasDev.Templify.Gui/App.axaml.cs
+++ b/TriasDev.Templify.Gui/App.axaml.cs
@@ -2,11 +2,8 @@
 // Licensed under the MIT License. See LICENSE file in the project root for full license information.
 
 using System;
-using System.Linq;
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
-using Avalonia.Data.Core;
-using Avalonia.Data.Core.Plugins;
 using Avalonia.Markup.Xaml;
 using Microsoft.Extensions.DependencyInjection;
 using TriasDev.Templify.Gui.Services;
@@ -28,11 +25,6 @@ public override void OnFrameworkInitializationCompleted()
     {
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
-            // Avoid duplicate validations from both Avalonia and the CommunityToolkit.
-            // More info: https://docs.avaloniaui.net/docs/guides/development-guides/data-validation#manage-validationplugins
-            DisableAvaloniaDataAnnotationValidation();
-
-            // Create MainWindow first
             MainWindow mainWindow = new MainWindow();
             desktop.MainWindow = mainWindow;
 
@@ -73,17 +65,4 @@ private void ConfigureServices(IServiceCollection services)
             throw new InvalidOperationException("MainWindow not available for FileDialogService");
         });
     }
-
-    private void DisableAvaloniaDataAnnotationValidation()
-    {
-        // Get an array of plugins to remove
-        DataAnnotationsValidationPlugin[] dataValidationPluginsToRemove =
-            BindingPlugins.DataValidators.OfType<DataAnnotationsValidationPlugin>().ToArray();
-
-        // remove each entry found
-        foreach (DataAnnotationsValidationPlugin plugin in dataValidationPluginsToRemove)
-        {
-            BindingPlugins.DataValidators.Remove(plugin);
-        }
-    }
 }
diff --git a/TriasDev.Templify.Gui/TriasDev.Templify.Gui.csproj b/TriasDev.Templify.Gui/TriasDev.Templify.Gui.csproj
index 68cbafa..e723a2a 100644
--- a/TriasDev.Templify.Gui/TriasDev.Templify.Gui.csproj
+++ b/TriasDev.Templify.Gui/TriasDev.Templify.Gui.csproj
@@ -14,12 +14,12 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Avalonia" Version="11.3.10" />
-    <PackageReference Include="Avalonia.Desktop" Version="11.3.10" />
-    <PackageReference Include="Avalonia.Themes.Fluent" Version="11.3.10" />
-    <PackageReference Include="Avalonia.Fonts.Inter" Version="11.3.10" />
-    <!--Condition below is needed to remove Avalonia.Diagnostics package from build output in Release configuration.-->
-    <PackageReference Include="Avalonia.Diagnostics" Version="11.3.10">
+    <PackageReference Include="Avalonia" Version="12.0.3" />
+    <PackageReference Include="Avalonia.Desktop" Version="12.0.3" />
+    <PackageReference Include="Avalonia.Themes.Fluent" Version="12.0.3" />
+    <PackageReference Include="Avalonia.Fonts.Inter" Version="12.0.3" />
+    <!--Avalonia 12 replaces Avalonia.Diagnostics with AvaloniaUI.DiagnosticsSupport (bridge to external DevTools, F12).-->
+    <PackageReference Include="AvaloniaUI.DiagnosticsSupport" Version="2.2.1">
       <IncludeAssets Condition="'$(Configuration)' != 'Debug'">None</IncludeAssets>
       <PrivateAssets Condition="'$(Configuration)' != 'Debug'">All</PrivateAssets>
     </PackageReference>
diff --git a/TriasDev.Templify.Gui/Views/MainWindow.axaml b/TriasDev.Templify.Gui/Views/MainWindow.axaml
index 1113119..5a6c553 100644
--- a/TriasDev.Templify.Gui/Views/MainWindow.axaml
+++ b/TriasDev.Templify.Gui/Views/MainWindow.axaml
@@ -30,7 +30,7 @@
             <TextBox Grid.Column="1"
                      Text="{Binding TemplatePath}"
                      IsReadOnly="True"
-                     Watermark="Select a .docx template file"
+                     PlaceholderText="Select a .docx template file"
                      Margin="10,0,10,0"/>
             <Button Grid.Column="2"
                     Content="Browse..."
@@ -43,7 +43,7 @@
             <TextBox Grid.Column="1"
                      Text="{Binding JsonPath}"
                      IsReadOnly="True"
-                     Watermark="Select a .json data file"
+                     PlaceholderText="Select a .json data file"
                      Margin="10,0,10,0"/>
             <Button Grid.Column="2"
                     Content="Browse..."
@@ -56,7 +56,7 @@
             <TextBox Grid.Column="1"
                      Text="{Binding OutputPath}"
                      IsReadOnly="True"
-                     Watermark="Output will be saved here"
+                     PlaceholderText="Output will be saved here"
                      Margin="10,0,10,0"/>
             <Button Grid.Column="2"
                     Content="Browse..."