By some freak of nature, today I'm having similar problems with my CM15A. I noticed that the timer was off by one hour due to Daylight Savings Time, so I thought I'd plug it in and refresh the time, etc. Big mistake.
I've never had any problems in the past having my Windows 10 computer recognizing my CM15A when I plug it in, until today. It does not recognize the device at all, even as an "unknown device" in Device Manager. I've tried all of the unplugging and battery removal steps to no avail. That was probably a big mistake because I'm sure it cleared the interface and I can't reload it.
I've also tried to attach it to my laptop (also Win 10) which I have never done. I installed a fresh copy of ActiveHome and still, the CM15A is not recognized at all in any way. Is there a way to install it manually?