Yet another report of problems with the Surface Pro 4. This time the symptoms involve a suddenly dead Type Cover, a missing driver — and no help from Microsoft. There are tantalizing hints that the bug arrived with a recent pushed software update, and it may affect some Surface Pro 3 machines as well.
Poster kzh91 on the Microsoft Answers forum describes the problem:
After a recent surface pro 4 firmware update, my 'surface type cover filter device' driver disappeared, and my type cover no longer works. … I have tried doing a restart, hard restart, uninstalling the existing keyboard drivers and clicking on scan for hardware changes, but the surface type cover filter device doesn't come back. My type cover was attached throughout this process. I do not wish to refresh windows as i don't want to have to reinstall everything, and i can't roll back the surface firmware updates.