SavePackage does not create uasset on disk


I have a strange behaviour I can not solve. I create assets from our level editor at runtime using the following code:

FString mount_point = full_path = FPaths::Combine( FPaths::GameSavedDir(), FString( "Player/Levels" ) );

FPackageName::RegisterMountPoint( "/PlayerData/Levels/", relative_dir );

USQLevelAsset * level_asset = nullptr;

const auto level_dir = "/PlayerData/Levels";
const auto path_name = FPaths::Combine( level_dir, LevelName.ToString() );
const auto level_file_name = FPaths::GetBaseFilename( path_name );

auto * package = LoadPackage( nullptr, *path_name, LOAD_None );

if ( package != nullptr )
    level_asset = FindObject<USQLevelAsset>( package, *level_file_name );
    package = CreatePackage( nullptr, *path_name );

if ( level_asset == nullptr )
    level_asset = NewObject< USQLevelAsset >( package, USQLevelAsset::StaticClass(), *level_file_name, RF_Public | RF_Standalone );

if ( ensure( level_asset != nullptr ) )
    level_editor.SaveToLevelAsset( level_asset );

    const auto file_name = FString::Printf( TEXT( "%s%s" ), *path_name, *FPackageName::GetAssetPackageExtension() );

    UPackage::SavePackage( package, /*level_asset*/ nullptr, EObjectFlags::RF_Public | EObjectFlags::RF_Standalone, *file_name );

    FAssetRegistryModule::AssetCreated( level_asset );


When I play our game in PIE, and save the asset, it is correctly displayed in the content browser, with a star on the icon, meaning it needs to be saved. But the asset does not exist physically on the disk, I have to save all the assets from the UE editor to have it created in the correct folder.

How can I save the package to disk at the same time? Because the issue I face is that when a player plays the game in standalone, and saves its level, the asset exists in memory, but not in the save folder.

Thanks !

Problem solved…

UPackage::SavePackage expects the filename to be the relative (or absolute?) file path, when I was passing the path of the file in its mounted folder…