Unable to mount root fs on unknown-block(179,6) [Solved]

Hello to all. I’ve been used my Raspberry Pi 2 for months with Mate 15 in a SD 8GB class 10 and without any problem.
Today, i download the new version 16 and i get “unable to mount root fs on unknown-block(179,6)”.
so, i reformated the SD (in windows 10 PC) and download anotehr iso from another server… but nothing, the same problem.
I read in the forum perhaps is a SD problem but i don’t know how to fixed. I pass chkdsk to the SD in windows, but nothing.
I have two SD 8GB class 10 and in both, the same problem.
please, can anyone help me?
thanks a lot.
asis

Please, can anyone help me? I am trying with two SD class 10 8GB and in both, the same problem, and i begin to be a bit desesperate :frowning:
thanks
Asis

and I have only a Win 10 PC to do the SD. trying with chkdsk gives no error.

I changed to a 16 GB SD card… and run. thanks anyway.
Asis