Question: On a laptop where was previously installed Windows 8.1 I was perfectly able to use the hibernation feature. I have upgraded to Windows 10 and now the hibernation feature is disabled. If I run a powercfg -a command it tells me that the hibernation is not available for a very strange reason to me.
It says, more or less since I am translating the text from another language, that the hibernation file type does not support the hibernation.

Does anybody have any idea of what this means?

I verified and on the root of my C: drive I have a hiberfil.sys if I enable the hibernation via the powercfg -h on and the file is removed if I issue the off command. Strangly the file size is only of 300MB when my installed RAM is 1.5GB.
I still have 50GB of free space and I am using an SSD drive.

Many thanks!

Answer: 
I'm assuming that hibernation is enabled (powercfg -h on)

Open command prompt as admin

Type: shutdown -h

If nothing happens, there are two posibilites:

1. you have not installed all drivers or some of them are invaild (most likly this is the problem)
2. you dont have sufficient free space on system drive
Hibernate option not shown even in settings tab. 
On my tablet Olivetti Graphos W810, originally win8.1, now win10, 2GB RAM, worked following theese steps:   

1. powercfg /h off   

2. freeing 1.5GB on C: (800MB as the file size was not enough :-/)   

3. powercfg /h /type full   

4. powercfg /h /size off   

5. powercfg /h /size 40%   

6. enable hibernation in start menu   

The type, before manually setting it as "full", was set as "reduced" and hibernation didn't show as available option. Moreover the size before freeing space was too small (405MB), in full type it can be raised, this fact helped too.
Bye
Daniel