Timeout detected. (control connection). x Lost connection

I upgraded from 5.15.9 to 5.17.7 and could not access any of (6) servers.
I am using FTP - no encryption - port 21.
I am running Windows 10 v2004
I tried starting a session but cannot find the log file (%TEMP%\!S.log)
I looked in c:\TEMP
If you can tell me how to access it, I'm happy to send it.
I tried going back to 5.15.9
I tried reinstalling 5.17.7
I contacted my service provided.
They said everything is fine at their end.
I contacted McAfee and they tried reinstalling their software.
I installed a different FTP.
Nothing works.
Everything was fine until I installed 5.17.7 2 days ago.
:(
Sue
mkitcowt@gmail.com

Do I understand correctly that even other FTP clients fail to connect to your servers?

martin wrote:

Do I understand correctly that even other FTP clients fail to connect to your servers?

Yes. I tried CoffeeCup Free. I know it sounds suspicious. But I was using WinSCP at about 1am Monday and transferring data, no problem. At some point I got a popup to upgrade. I think I clicked No initially but later thought, I might as well get the latest rev.
Went to bed and later in the morning I went to resume my work and kept timing out.
I couldn't connect to any of 6 servers.
And btw ... First I tried winscp.net>eng>docs/message_timeout_detected, increased the time interval, but no luck.
I then started reading the link to learn about FTP connection modes, but my head started to explode.
That's when I contacted my cable company, then McAfee.
I also looked into changing firewall exceptions.
Control Panel>System and Security>Windows Defender Firewall>Check firewall status (see att.)
But it looks like McAfee handles this.
Don't know if it is significant.
~Sue
mkitcowt@gmail.com

Sorry, but this is likely a mere coincidence. I cannot imagine how WinSCP upgrade could prevent other clients from working. There something wrong with your network connection.

Update:
I tried Filezilla and it worked!
Still don't know what the problem is with WinSCP (or CoffeeCup) but I found the session log (att.)

So please post verbose FileZilla log file as well.

Here it is.

The FileZilla session is encrypted. Did you try enabling the encryption in WinSCP too?

Bingo! I code but I'm not as tech savvy when it comes to this. Not sure how my setting were before the upgrade, but it was working. So, the upgrade defaulted to No Encryption?
Thanks for your help!

mkitcowt wrote:

So, the upgrade defaulted to No Encryption?

FTP connections in WinSCP default to no encryption (and they always did).