iis error code 0x80070520. A specified logon session does not exist

I have received that error when I'm trying to bind a certificate on a website. I have read some information about it. But they did not work for me. They said to set all permissions to the actual account (administrator) on C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys but, when I apply the permissions on the folder, I got a warning dialog saying that I do not have permissions on some files in the folder.

The certificate file extension is crt. And I also converted it into .pfx file. With both files I got the same problem. With the .pfx I checked ensure that the “Allow this certificate to be exported” is checked.

How can I fix that problem? Is it the server or my certificate? I am on Windows server 2012.

I just fixed it. It was maybe a problem installing the certificate key. I installed Digicert. With it, from the certificates list, I select the certificate I was having problem with, then click on the Test key button, it gave me an error like certificate key problem then I click repair. It fixed it.