As I mentioned before, it seems you are not using the proper key when accessing the instance. If you accessed the instance using the SSH connection before, you should have changed something in the configuration of the tool or in the instance that makes the connection fail. Could you please review the guide again?
Regarding the Support tool file, please note that you need to use Filezilla or any other SFTP tool to get the file. Putty is not the right tool to do so
Could you please let us know how we can obtain that error message so we can investigate it further? We would like to know if you installed any plugin or something in order to get the status of the wp-cron. Please share with us any step you followed to get that info (log in to the dashboard, click on ..., install ...)
Sorry @zmed.alex, I didn't fully understand your message. Did the cron work in a fresh instance? If that's the case, I think that the configuration you are using in the first server has conflicts with the wp-cron file.