I had a similar issue after updating to the Win10 Creators update (850 EVO 250GB). Everything had been fine before then. After the update, the drive didn't even show up in Magician despite the fact that it was the system/boot drive, was present in Device Manager, and was obviously usable as I was able to boot from it. I noticed that a "Marvel 91xx" driver update had shown up among my installed programs in Windows "Programs and Features"; I guess it came along with the update. I uninstalled that, rebooted, and I was back in business. After that the drive showed up in Magician, and I was able to re-enable rapid mode.
... View more