Same issue here from customers this morning and on our own Macs. FTP only works with SSL turned off, which is not a good move in todays world.
We use Dreamweaver CS6, as do many others in web dev. I notice in FTP SSL configs it has TLSv1, changing it to v2 does not work. Is there any other workaround as this has to work. There is no way we can force customers to move to Creative Cloud, nor can we!