No access to FTP intranet servers if upgrade KDE Plasma + KDE frameworks

Scenario: Intranet with Internet access via HTTP proxy and local FTP servers.
Operating System: openSUSE Tumbleweed 20230613
KDE Plasma Version: 5.27.5
KDE Frameworks Version: 5.107.0
Qt Version: 5.15.9

For years I have been using Plasma on a corporate intranet where HTTP authentication is required to access the Internet. Windows domain authentication is required to access shared folders on domain computers, using the SMB protocol. An important detail here is that FTP access is to local servers INSIDE the intranet, not to servers outside, i.e. Internet access is not required for FTP.

For years, I got to work all fine doing configuring the system proxy and the KDE proxy (as you know, they are independent) to use HTTP(S) proxy.

The problem with this configuration was that KDE applications, such as Dolphin, when making an FTP connection, would try to use the proxy, so it would eventually fail. The workaround I had to find years ago, is to create a PAC file and use it only in the KDE proxy configuration (like I need to do in Firefox). In that PAC file, I put that if the path does NOT contain HTTP://, proxy is NOT required. It has always worked without further problems (and I don’t know if there is an easier way to do it, which would be wonderful).

However, for a few months now, every time I upgrade Plasma and Frameworks, Dolphin and even Krusader are unable to continue accesing the local FTP seervers and I have to downgrade to the previous system snapshot to be able to continue working. I try every 3 weeks or so to perform an update and check again if I have FTP access to the local servers, in case it is a one-off bug, but as of today (7 May 2024) any update breaks normal FTP access.
In this regard, I have verified that it happens even with the latest LIVE versions of Tumbleweed (configuring proxy as in my real installed system).

For me it is ESSENTIAL to continue to be able to access these servers with FTP. In the meantime, I cannot upgrade.

And it’s clear to me that it must be a KDE problem, because if I use the CAJA file manager to access these servers, it works!!! But of course, CAJA doesn’t offer me all the possibilities that Dolphin and Krusader do, so it’s a “patch” and not a solution to the problem.

I created a bug in KDE, but nobody has been interested in the problem, so I ask the community in case there is someone reading here who has the same scenario and the solution to the problem.

Thanks for reading

UPDATE: This issue about proxy behaviour en Plasma was reported years ago.

You did the right thing, reporting the bug.
Only developers can do anything about it.
Please provide a crash report if you can that would be very very helpful.
I added a comment to the bug report.

I don’t feel very comfortable (it’s risky) having to do the test, because it’s the computer I use every day in development and so I can’t afford the risk of it failing “backing up” (as well as backing up in case it fails). All this is taking time, but I will try to get more information from the logs as soon as possible. Also, there is a possibility that I might try it on another computer, where I don’t necessarily require FTP access to the servers.

Thanks again for your support, Meven

@meven is saying that you should be attaching a crash log of the program(s) in question, not the system itself.

I could have sworn I had replied to this last message, but I can’t see it!!! To sum up, in my message I replied that Dolphin does not stop working, so there is no “Crash report” to contribute. It simply displays the messages I supplied in the console.