[Nop Commerce 3.60] Log in doesn't work for any user even admin

I have an issue with the log in, any user can't login. I've registered with new users and these users can't log in, older users can't log in. No error is launch, no error is register in the log, when the users write their user and password and click on "Log in" the web is launched to main page and user is not register.

Database is working properly, ecommerce is working propertly, I've restarted the application even the server, I've deleted cookies and history files, I've try in several web browsers: Chrome, firefox, IE.

Sadly with this issue I can't go to administration side.

Can you help me?

Url: https://www.iniciativas3d.com/iniciativas3d

Best regards

Try setting up a Machine Key

Same issue.

I'm adding next line under <system.web>
<machineKey decryptionKey="xxxxx...xxxx" validationKey="xxx..xxx" />
I'm reboot the application and doesn't help.

Is your server 'local' or hosted?  If local, can you try it with a browser running on that server?

no, server is hosted, anyway, I've tried into a local browser [in the hosted server] and same issue.