diff --git a/src/UniversalValveToolbox/UI/FormAddons.cs b/src/UniversalValveToolbox/UI/FormAddons.cs
index 31c30af..7269808 100644
--- a/src/UniversalValveToolbox/UI/FormAddons.cs
+++ b/src/UniversalValveToolbox/UI/FormAddons.cs
@@ -9,6 +9,7 @@ using System.Collections.Generic;
 using UniversalValveToolbox.Utils;
 using System.Globalization;
 using System.Collections;
+using EpicMorg.SteamPathsLib;
 
 namespace UniversalValveToolbox {
     public partial class FormAddons : Form {
@@ -29,7 +30,7 @@ namespace UniversalValveToolbox {
                 .Cast<DictionaryEntry>()
                 .ToArray();
 
-            model = new FormAddonViewModel(dataProvider.Addons, dataProvider.Engines, categories);
+            model = new FormAddonViewModel(dataProvider.Addons, dataProvider.Engines.Where(engine => SteamPathsUtil.GetSteamAppDataById(engine.Appid) != null).ToArray(), categories);
 
             UpdateAddonsComboBox();
             UpdateAddonCategoryComboBox();
diff --git a/src/UniversalValveToolbox/UI/FormProjects.cs b/src/UniversalValveToolbox/UI/FormProjects.cs
index 230ca12..476b22f 100644
--- a/src/UniversalValveToolbox/UI/FormProjects.cs
+++ b/src/UniversalValveToolbox/UI/FormProjects.cs
@@ -1,4 +1,5 @@
-using kasthack.binding.wf;
+using EpicMorg.SteamPathsLib;
+using kasthack.binding.wf;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -19,8 +20,8 @@ namespace UniversalValveToolbox {
 
         public FormProjects() {
             InitializeComponent();
-
-            model = new FormProjectViewModel(dataProvider.Projects, dataProvider.Engines);
+             
+            model = new FormProjectViewModel(dataProvider.Projects, dataProvider.Engines.Where(engine => SteamPathsUtil.GetSteamAppDataById(engine.Appid) != null).ToArray());
 
             UpdateComboBoxProject();
             UpdateComboBoxEngine();