Windows server is working flawlessly for me. There’s a bug that prevents closed captioning when using hardware transcoding from a server with Intel HD Graphics. It’s not really a Channels bug, it’s a Ffmpeg bug in its Intel Quicksync encoding engine. I filed a bug report a couple of months ago, but there hasn’t been any work done on it.
Bottom line is, if you want closed captioning from a Channels Windows server on an Intel machine, you need to select software transcoding. Performance slows down a bit and CPU usage, in my case, jumps from around 15% to 50% on an i7.