Thanks for stepping in. After that, Unreal tells me:
LogPackageName: Error: DoesPackageExist: DoesPackageExist FAILED: ‘MyNewAsset’ is not a standard unreal filename or a long path name. Reason: Path should start with a ‘/’
LogAssetTools: Error: /Game/Path/To/MyAsset - /Game/Path/To/MyAsset.MyAsset to /Game/Path/To/MyNewAsset.MyNewAsset.MyNewAsset.MyNewAsset: Name may not contain the following characters: .