diff --git a/base/VulkanModel.hpp b/base/VulkanModel.hpp
index daf8dc16..20c8ea10 100644
--- a/base/VulkanModel.hpp
+++ b/base/VulkanModel.hpp
@@ -184,6 +184,10 @@ namespace vks
 			free(meshData);
 #else
 			pScene = Importer.ReadFile(filename.c_str(), flags);
+			if (!pScene) {
+				std::string error = Importer.GetErrorString();
+				vks::tools::exitFatal(error + "\n\nThe file may be part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", "Error");
+			}
 #endif
 
 			if (pScene)
diff --git a/base/VulkanTexture.hpp b/base/VulkanTexture.hpp
index b9311862..456bf94b 100644
--- a/base/VulkanTexture.hpp
+++ b/base/VulkanTexture.hpp
@@ -92,7 +92,9 @@ namespace vks
 			// Textures are stored inside the apk on Android (compressed)
 			// So they need to be loaded via the asset manager
 			AAsset* asset = AAssetManager_open(androidApp->activity->assetManager, filename.c_str(), AASSET_MODE_STREAMING);
-			assert(asset);
+			if (!asset) {
+				vks::tools::exitFatal("Could not load texture from " + filename + "\n\nThe file may be part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", "Error");
+			}
 			size_t size = AAsset_getLength(asset);
 			assert(size > 0);
 
@@ -105,7 +107,7 @@ namespace vks
 			free(textureData);
 #else
 			if (!vks::tools::fileExists(filename)) {
-				vks::tools::exitFatal("Could not load texture from " + filename, "File not found");
+				vks::tools::exitFatal("Could not load texture from " + filename + "\n\nThe file may be part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", "Error");
 			}
 			gli::texture2d tex2D(gli::load(filename.c_str()));
 #endif		
@@ -570,7 +572,9 @@ namespace vks
 			// Textures are stored inside the apk on Android (compressed)
 			// So they need to be loaded via the asset manager
 			AAsset* asset = AAssetManager_open(androidApp->activity->assetManager, filename.c_str(), AASSET_MODE_STREAMING);
-			assert(asset);
+			if (!asset) {
+				vks::tools::exitFatal("Could not load texture from " + filename + "\n\nThe file may be part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", "Error");
+			}
 			size_t size = AAsset_getLength(asset);
 			assert(size > 0);
 
@@ -583,7 +587,7 @@ namespace vks
 			free(textureData);
 #else
 			if (!vks::tools::fileExists(filename)) {
-				vks::tools::exitFatal("Could not load texture from " + filename, "File not found");
+				vks::tools::exitFatal("Could not load texture from " + filename + "\n\nThe file may be part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", "Error");
 			}
 			gli::texture2d_array tex2DArray(gli::load(filename));
 #endif	
@@ -779,7 +783,9 @@ namespace vks
 			// Textures are stored inside the apk on Android (compressed)
 			// So they need to be loaded via the asset manager
 			AAsset* asset = AAssetManager_open(androidApp->activity->assetManager, filename.c_str(), AASSET_MODE_STREAMING);
-			assert(asset);
+			if (!asset) {
+				vks::tools::exitFatal("Could not load texture from " + filename + "\n\nThe file may be part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", "Error");
+			}
 			size_t size = AAsset_getLength(asset);
 			assert(size > 0);
 
@@ -792,7 +798,7 @@ namespace vks
 			free(textureData);
 #else
 			if (!vks::tools::fileExists(filename)) {
-				vks::tools::exitFatal("Could not load texture from " + filename, "File not found");
+				vks::tools::exitFatal("Could not load texture from " + filename + "\n\nThe file may be part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", "Error");
 			}
 			gli::texture_cube texCube(gli::load(filename));
 #endif