I tested locally from an authorized point of access to their FTP server. FileZilla can execute the Connect() successfully. However, the Rebex component cannot do the Connect() and still returns the same common algorithm message. I am starting to believe that this Rebex component is not capable of handling SFTP on all FTP servers, where one of them would be GlobalSCAPE.
Has anyone been able to connect to a FTP server using GlobalSCAPE with the Rebex component from .NET?