Error: Connection got closed prematurely, some technical error

My ftp site is mickftpsite.com, 99.242.126.196

I messed up some technical thing with my win 10 IIS ftp site. I do not know what it is. I ran ftptest.net with this result...
Status: Resolving address of mickftpsite.com
Status: Connecting to 99.242.126.196
Warning: The entered address does not resolve to an IPv6 address.
Status: Connected, waiting for welcome message...
Error: Connection got closed prematurely

The warning is of no consequence. The various reasons to get the "closed prematurely" message do not seem to apply. After much trying of various things I decided to start over from the beginning.

I started over like this...
I checked...
ports forwarded in router 21, 80, 443, 30000-65000

In firewall...
open those ports both inbound and outbound,
allowed Microsoft ftp server private and public,
allowed ftp traffic in, 4 categories

Also to get a clean new install...
stopped ftp service
removed ftp site from iis
turned ftp off in Windows Features [uninstall]
created a new folder for the ftp root and checked permissions: c:\inetFtp
Re-installed iis ftp [Features on]
restarted IIS and Ftp Service

I meticulously went thru the install steps following 2 or 3 of the many on line blogs
Have gone through all of those settings a few times and they are each OK

A couple of other things..

I do not know what these actually do but I ran them hoping that something in the configuration would get reset...

net stop WAS

net start w3svc

So conclusion, something technical in the background, not necessarily in inetmgr, possibly in the Registry, is messed up. Any suggestions are appreciated 🙂

Thank you,

Mick