diff --git a/Sources/UntoldEngine/Scenes/SceneSerializer.swift b/Sources/UntoldEngine/Scenes/SceneSerializer.swift
index 1d0106ade..a434e7d38 100644
--- a/Sources/UntoldEngine/Scenes/SceneSerializer.swift
+++ b/Sources/UntoldEngine/Scenes/SceneSerializer.swift
@@ -1311,21 +1311,24 @@ public func serializeScene() -> SceneData {
         var shouldApplyIBL = applyIBL
 
         if hdrURL.isEmpty == false {
-            var hdrExists = false
-
-            // Check in user's asset base path (HDR folder)
-            if let basePath = assetBasePath {
-                let hdrPath = basePath.appendingPathComponent("HDR").appendingPathComponent(hdrURL)
-                hdrExists = FileManager.default.fileExists(atPath: hdrPath.path)
+            // Resolve through the same search LoadingSystem/generateHDR already use
+            // (assetBasePath/HDR, app bundle, engine bundle) rather than only checking
+            // assetBasePath/HDR directly. The active HDR may legitimately be one of the
+            // engine's built-in defaults (e.g. teatro_massimo_2k.hdr), which lives in the
+            // engine's resource bundle, not the project's asset folder -- checking only
+            // assetBasePath/HDR falsely reported those as "not found" and disabled IBL.
+            let nsName = hdrURL as NSString
+            let providedExtension = nsName.pathExtension
+            let candidates: [(base: String, ext: String)] = providedExtension.isEmpty
+                ? ["hdr", "exr", "png"].map { (hdrURL, $0) }
+                : [(nsName.deletingPathExtension, providedExtension)]
+
+            let hdrExists = candidates.contains { candidate in
+                LoadingSystem.shared.resourceURL(forResource: candidate.base, withExtension: candidate.ext, subResource: nil) != nil
+            }
 
-                if !hdrExists {
-                    Logger.logWarning(message: "[SceneSerializer] HDR file not found in assets: \(hdrURL), disabling IBL")
-                    validatedHDR = nil
-                    shouldApplyIBL = false
-                }
-            } else {
-                // No asset base path set, can't validate
-                Logger.logWarning(message: "[SceneSerializer] No asset base path set, cannot validate HDR")
+            if !hdrExists {
+                Logger.logWarning(message: "[SceneSerializer] HDR file not found in assets: \(hdrURL), disabling IBL")
                 validatedHDR = nil
                 shouldApplyIBL = false
             }
@@ -1623,12 +1626,14 @@ public func deserializeScene(
             hdrURL = hdr
         } else {
             hdrURL = ""
+            hdrDirectoryURL = nil
         }
     } else {
         applyIBL = false
         renderEnvironment = false
         ambientIntensity = 0.4
         hdrURL = ""
+        hdrDirectoryURL = nil
     }
 
     if let colorGrading = sceneData.colorGrading {
diff --git a/Sources/UntoldEngine/Systems/LoadingSystem.swift b/Sources/UntoldEngine/Systems/LoadingSystem.swift
index 780a0068e..afd6e00a5 100644
--- a/Sources/UntoldEngine/Systems/LoadingSystem.swift
+++ b/Sources/UntoldEngine/Systems/LoadingSystem.swift
@@ -109,9 +109,16 @@ public func getResourceURL(resourceName: String, ext: String, subName: String?)
 
     // Flat layout (no top-level "Assets")
     var searchPaths: [[String]] = [
+        // Nested form (Models/<name>/<name>.<ext>) is checked first, then the flat
+        // form (Models/<name>.<ext>) the Editor's asset exporter actually writes --
+        // it cooks the runtime asset into the category root, beside the per-model
+        // support folder, rather than inside it. See RuntimeExportLocation.swift.
         ["Models", resourceName, "\(resourceName).\(ext)"],
+        ["Models", "\(resourceName).\(ext)"],
         ["StreamModels", resourceName, "\(resourceName).\(ext)"],
+        ["StreamModels", "\(resourceName).\(ext)"],
         ["Animations", resourceName, "\(resourceName).\(ext)"],
+        ["Animations", "\(resourceName).\(ext)"],
         ["HDR", "\(resourceName).\(ext)"],
         ["Gaussians", "\(resourceName).\(ext)"],
         ["Scripts", "\(resourceName).\(ext)"],
@@ -132,8 +139,11 @@ public func getResourceURL(resourceName: String, ext: String, subName: String?)
         // Then try structured subdirectories
         let searchPaths: [[String]] = [
             ["Models", resourceName, "\(resourceName).\(ext)"],
+            ["Models", "\(resourceName).\(ext)"],
             ["StreamModels", resourceName, "\(resourceName).\(ext)"],
+            ["StreamModels", "\(resourceName).\(ext)"],
             ["Animations", resourceName, "\(resourceName).\(ext)"],
+            ["Animations", "\(resourceName).\(ext)"],
             ["HDR", "\(resourceName).\(ext)"],
             ["Gaussians", "\(resourceName).\(ext)"],
             ["Scripts", "\(resourceName).\(ext)"],
diff --git a/Sources/UntoldEngine/Utils/FuncUtils.swift b/Sources/UntoldEngine/Utils/FuncUtils.swift
index 33107a41e..2b1cc09ad 100644
--- a/Sources/UntoldEngine/Utils/FuncUtils.swift
+++ b/Sources/UntoldEngine/Utils/FuncUtils.swift
@@ -53,7 +53,7 @@ private func makeHDRTexture(width: Int, height: Int, label: String) throws -> MT
         1 + floorf(log2f(fmaxf(Float(width), Float(height))))
     )
 
-    guard let texture = renderInfo.device.makeTexture(descriptor: descriptor) else {
+    guard let device = renderInfo.device, let texture = device.makeTexture(descriptor: descriptor) else {
         throw LoadError.textureCreationFailed
     }
     texture.label = label
@@ -154,6 +154,10 @@ public func loadTexture(
 }
 
 public func loadImage(_ textureName: String, from directory: URL? = nil) throws -> URL {
+    guard !textureName.isEmpty else {
+        throw LoadError.urlCreationFailed(textureName)
+    }
+
     if let directory {
         let fileURL = directory.appendingPathComponent(textureName)
         if FileManager.default.fileExists(atPath: fileURL.path) {