I was using the latest drivers available for the EMU 0404 USB 2.0 audio device in the previous build (9926) without any problems. But when system updated to preview build 10041, the driver stopped working.
Applications trying to output audio now freezes and "The audio service is not running" message is displayed at the sound volume icon on the taskbar.
Uninstalling and reinstalling driver didn't solve the issue.
By the way, the driver version is 1.40 for Windows 7 x64 and it is a beta release because this device is no longer manufactured.
Now I wonder if it is a temporary state that will be resolved in the final release or this kind of old (but perfectly working) usb audio devices won't be supported any more.