Getting visualforce page error as List has no rows for assignment to SObject.  An unexpected error has occurred. Your development organization has been notified.
Here is my page controller.

Controller-
public class MyFirstController {


    private final Account account;

    public MyFirstController () {

        account = [SELECT Id, Name, Site FROM Account

                   WHERE Id = :ApexPages.currentPage().getParameters().get('id')];

    }

 
    public Account getAccount() {

        return account;

    }

 
    public PageReference save() {

        update account;

        return null;

    }

}