Error message - new laptop

Hi
This is weird! Been using WinSCP for years across a number of Win10/11 PCs without any issues at all. I just bought a brand new ASUS Win11 laptop. I exported the settings/config file and then installed WinSCP on my new machine. I imported all the sites and all seemed well.
However, when I launch the App and attempt to connect to a site, I'm getting a random error message. Sometimes it connects to sites, and sometimes it doesn't – the message says 'Network Error. Software caused connection abort'. Any thoughts anyone? Big thanks, Steve

Can you connect anyhow from that new laptop? Using any other client with the same protocol?

Thanks for the quick reply.

Yes, the laptop connects to the interweb with other apps ie Edge, Firefox and I can send and receive emails. It seems very intermittent. Sometimes it connects with WinSCP, sometimes it doesn't. A second PC using the same setup has no issues.

Weird!

Steve

OK, after quite a bit of experimentation, changing various settings, I seem to have solved it!
I'm not techy enough to know WHY it's now fixed, perhaps someone can enlighten me?
Especially given that both my Desktop and this new laptop use the same site connection settings (the same exported config file - the Desktop always connects, but my brand new laptop fails to connect to a number of pre-configged sites on a random basis. The solution was to switch from 'Auto' to 'IPv4' in the 'advanced menu' for the particular sites that were failing. So, anyone know WHY that would sort things out? Both machines are Windows 11 - the desktop is around 5 years old and the troublesome laptop is about 5 minutes old!
Cheers, Steve

Good news. The old machine might have IPv6 disabled.

If you want to dig further into this, please post logs of both successful and failing connection (both from the new laptop).

Cheers Martin. yes, I'll provide some logs. It's been a while since I 'switched on' logs, can you remind me how to set it up and where the logs are stored?

Thanks, Steve

Hi Martin

OK, I figured out how to create the logs.
Zip file attached.

'sftp' - is the connection that works by setting it to IPv4

'Test' is a cloned connection of the above with connection set to 'auto' (that always fails on first connection, but repeated logins eventually allow it to connect). The same settings (ie with all my connections set to 'auto') have always worked on every other Windows machine - it just seems that this laptop is a bit fussy. technically, there's nothing different about this new laptop compared to the one it replaces. Both are Windows 11, both used the same exported settings.

The "Steve---test.xml" is an (empty) XML log, not the session log.

Hi Martin

Thanks for the quick reply. Here's the test.log file - sorry about that... I blame the Gin :)

Indeed, your host has both IPv6 and IP4 address. With "Auto", WinSCP uses the IPv6 address and that does not work well. Do other SFTP client work correctly when using IPv6 address? Though I've actually asked you for "Auto" logs for both successful and failing connection.

Hi Martin

Yes, every other device here connects without issue. I have WinSCP installed on three Windows machines. As I mentioned, I used the exported settings for all three PCs – so the settings are the same. The only difference at the moment is that the 'troublesome' PC is a brand new Windows 11 device whilst the other two are Windows 10. Having said that, the laptop that immediately preceded this one was also Windows 11 too – and that worked with the same configuration file and I never had a problem.

I also tried installing FileZilla and that had problems connecting on the laptop too.

I'm sorry, I don't understand your point about 'auto logs for both successful and failing connections'. In short, ANY connection on the laptop that's set to Auto fails (but eventually connects after multiple tries). If I take one of the connections and clone it, but switch the clone to Auto and set the original to IPv4, the original connects as expected, but the clone does not. In other words, the 'test connection' I sent you is in fact a clone of the 'Steve' connection in terms of settings.

In short,
'Test' = Auto
'Steve' = IPv4
Steve = Test (apart from the IPv setting)

Let me know if I've understood you correctly and if I can supply any further information.

To me, it all seems to point to a setting somewhere on the new laptop – maybe outside of WinSCP??? – but I think I've checked all the usual suspects and nothing stands out as being different to the other Windows 10 PCs.
Thanks for your patience.
Steve

Kind of answering my owner question here (I think!). It's certainly an IPv6 issue because if I add a tweak to the registry to prioritise IPv4 over IPv6 (https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/configure-ipv6-in-windows) then everything works as it should ie Connection set to 'Auto' within WinSCP allows me to connect, whereas before, I had to switch it to IPv4. I know it all amounts to the same thing, but I'm still intrigued as why a brand new laptop should exhibit these issues whereas none of my other PCs running WinSCP have a problem. Love technology! :) Steve

Well, before you wrote "It seems very intermittent. Sometimes it connects with WinSCP, sometimes it doesn't.". So if it is actually that "ANY connection on the laptop that's set to Auto fails (but eventually connects after multiple tries)", the please post a log that shows all that (the failure and the eventual success).

When asking about "other SFTP client", I've meant other SFTP client software on the same device/machine. Not other devices.

Hi Martin

Thanks for yours - and the clarification. Appreciate your suggestion of logging the continued attempts (that eventually connect) but realistically, that might require about an hour for each connection - sometimes it's that long before it actually connects - and I have about 10 connections! 😮. Currently, I don't have the time to try this given my workload at the moment. Based on my needs, I'm satisfied that the registry tweak I mentioned previously provides a practical workaround - even if it doesn't explain what's going on.

Thanks for developing this App. I can live with this issue, but I guess I was just slightly wrong-footed when it mis-behaved on this new laptop (first time ever, on any of my PCs past and present).

Perhaps we might close the ticket on this one, and if things get a little easier at my end, I might invest some time in your suggestion.
Thanks for all your suggestions so far. Onwards and upwards ehh?!?!

Steve