BOOTCAMP partition cannot be mounted

After working in Windows for a couple of days, then booting back to OSX - I cannot mount my BOOTCAMP partition in Mac OS X any more. Disk utility shows BOOTCAMP as "greyed out". Trying to mount throws an error "The disk BOOTCAMP could not be mounted. Try running First Aid". I cannot run First Aid because it is also greyed out.

I still can boot into Windows just fine via alt/boot. Moreover even Parallels can boot the Bootcamp partition just fine! (I mean, from OSX, as a virtual machine).

PS. I'm using Yosemite, and Windows 10 Bootcamp.

PPS. If I do this:

# cd /Volumes
# mkdir /Volumes/Bootcamp
# sudo mount_ntfs /dev/disk0s4 /Volumes/Bootcamp

It works fine. But it mounts it readonly, also I want it to mount automatically on startup, like it was before...

UPDATE: After digging through the system log I found this: "Windows is hibernated. Will not be able to remount read-write. Run chkdsk." - A-HA! This must be it.

But its not hibernated... Ok, guess I have to boot into windows again and shut-down/restart it a couple of times to clear the hibernation flag...

Solution 1:

Basically, what worked is booting to Windows natively and shutting it down several times to clear the hibernation flag. Also, disabled hibernation via power-management and via powercfg /h off.