diff --git a/backend/src/Squidex/Areas/Api/Controllers/Assets/AssetContentController.cs b/backend/src/Squidex/Areas/Api/Controllers/Assets/AssetContentController.cs
index 820364ded..7588efb6c 100644
--- a/backend/src/Squidex/Areas/Api/Controllers/Assets/AssetContentController.cs
+++ b/backend/src/Squidex/Areas/Api/Controllers/Assets/AssetContentController.cs
@@ -34,6 +34,7 @@ namespace Squidex.Areas.Api.Controllers.Assets
     {
         private readonly IAssetFileStore assetFileStore;
         private readonly IAssetQueryService assetQuery;
+        private readonly IAssetLoader assetLoader;
         private readonly IAssetStore assetStore;
         private readonly IAssetThumbnailGenerator assetThumbnailGenerator;
 
@@ -41,12 +42,14 @@ namespace Squidex.Areas.Api.Controllers.Assets
             ICommandBus commandBus,
             IAssetFileStore assetFileStore,
             IAssetQueryService assetQuery,
+            IAssetLoader assetLoader,
             IAssetStore assetStore,
             IAssetThumbnailGenerator assetThumbnailGenerator)
             : base(commandBus)
         {
             this.assetFileStore = assetFileStore;
             this.assetQuery = assetQuery;
+            this.assetLoader = assetLoader;
             this.assetStore = assetStore;
             this.assetThumbnailGenerator = assetThumbnailGenerator;
         }
@@ -119,9 +122,17 @@ namespace Squidex.Areas.Api.Controllers.Assets
                 return StatusCode(403);
             }
 
-            if (asset != null && queries.Version > EtagVersion.Any && asset.Version != queries.Version && Context.App != null)
+            if (asset != null && queries.Version > EtagVersion.Any && asset.Version != queries.Version)
             {
-                asset = await assetQuery.FindAsync(Context, asset.Id, queries.Version);
+                if (Context.App != null)
+                {
+                    asset = await assetQuery.FindAsync(Context, asset.Id, queries.Version);
+                }
+                else
+                {
+                    // Fallback for old endpoint. Does not set the surrogate key.
+                    asset = await assetLoader.GetAsync(asset.AppId.Id, asset.Id, queries.Version);
+                }
             }
 
             if (asset == null)
diff --git a/backend/tests/Squidex.Domain.Apps.Entities.Tests/Contents/TestData/FakeUrlGenerator.cs b/backend/tests/Squidex.Domain.Apps.Entities.Tests/Contents/TestData/FakeUrlGenerator.cs
index 7853dd3d0..995699c2c 100644
--- a/backend/tests/Squidex.Domain.Apps.Entities.Tests/Contents/TestData/FakeUrlGenerator.cs
+++ b/backend/tests/Squidex.Domain.Apps.Entities.Tests/Contents/TestData/FakeUrlGenerator.cs
@@ -36,11 +36,6 @@ namespace Squidex.Domain.Apps.Entities.Contents.TestData
             return $"contents/{schemaId.Name}/{contentId}";
         }
 
-        public string AppSettingsUI(NamedId<DomainId> appId)
-        {
-            throw new NotSupportedException();
-        }
-
         public string AssetsUI(NamedId<DomainId> appId, string? query = null)
         {
             throw new NotSupportedException();