Boot Error: Failure writing sector 0x21c8800 to 'hd0'

[Aljosa]

Hello GRUB developers,
I would like to inform you about annoying error that appears on my 
screen during the startup process every time I turn on the computer:

"failure writing sector 0x21c8800 to 'hd0'
press any key to continue..."

Here's my scenario:
Optimus laptop Lenovo Y700-17ISK (Intel Core i7-6700HQ/RAM 16GB/SSD 
512GB/Nvidia GTX960M 4GB)
BIOS CDCN35WW 03/29/2016
EFI v2.40 by LENOVO
Operating system: Ubuntu 16.04, kernel 4.4.X; kernel 4.6.2; kernel 
4.7-rc3.

This bug does not prevent the system from booting - both if I press or 
if I don't press any key system after 10-15 seconds continue to boot up 
before the Ubuntu wallpaper appears when it asks me for username and 
password. Recently I installed Windows 10 alongside with Ubuntu. Windows 
boots up fast and perfectly fine without any error. I used some tools 
which says that SSD health is excellent.

Thanks in advance for any help, please find attached my dmesg output.
Aljosa

dmesg_output.txt
Description: Text document