Bug 477081

> Dolphin crashes and is unable to access the local FTP paths (the same happens with Krusader

Please provide a crash trace, that will be extremely useful to find the issue origin.
There should be a drkonqi notification to help you do that.

Otherwise you can follow you distro steps https://en.opensuse.org/openSUSE:Bugreport_application_crashed#Install_-debuginfo_Packages

The issue is more likely to be in KIO  Framework that handles the ftp implementation.

> KDE Plasma Version: 5.27.5
> KDE Frameworks Version: 5.107.0

If you have the chance to test with a live iso with Plasma 6, that would be interesting.

I have again done a more extensive test on this, which is why I have changed the title of this thread. 
We started from a pre-Plasma 6 version of Tumbleweed where accessing folders on intranet servers with the FTP, FISH and SMB protocols (on a Windows domain) worked fine on an intranet with an HTTP proxy that requires a username and password.
After upgrading to any version of Plasma 6, none of the protocols work. I noticed that Dolphin, on the first attempt to access an FTP service after upgrading, asked for the proxy username and password, when in fact it should NOT ask for that information after parsing the request if it uses the PAC file. In other words, Plasma is now ignoring the directives in the PAC file (attached).

I launched Dolphin from console, and attached here error showed while trying to reach any of the servers folders using FTP, FISH or SMB.

Created attachment 169361 [details]
PAC file directives

Basically, the PAC file says "only use proxy for http protocol" (so no for FTP, FISH or SMB)

Created attachment 169362 [details]
Errors showed when trying to access remote folders

I don't attach a "crash" file cause basically Dolphin doesn't crash, simply doesn't work like before upgrading.

> Dolphin shows an unexpected error, can't access to the FTP path. Console shows these messages:
(process:13253): GLib-CRITICAL **: 15:12:52.440: g_uri_get_scheme: assertion 'uri != NULL' failed
(process:13253): GLib-CRITICAL **: 15:12:52.440: g_uri_get_scheme: assertion 'uri != NULL' failed
(process:13253): GLib-CRITICAL **: 15:12:52.440: g_str_has_prefix: assertion 'str != NULL' failed
(process:13253): GLib-CRITICAL **: 15:12:52.440: g_uri_get_scheme: assertion 'uri != NULL' failed
(process:13253): GLib-CRITICAL **: 15:12:52.440: g_str_has_prefix: assertion 'str != NULL' failed
(process:13253): GLib-CRITICAL **: 15:12:52.440: g_uri_get_scheme: assertion 'uri != NULL' failed
(process:13253): GLib-CRITICAL **: 15:12:52.440: g_str_has_prefix: assertion 'str != NULL' failed
(process:13253): GLib-CRITICAL **: 15:12:52.440: g_uri_to_string: assertion 'uri != NULL' failed

This looks like libproxy is crashing, so there's a bug in libproxy and/or your configuration is not valid.

IMHO, I think we can rule out my system configuration, since they are two different computers, on the same network, and that configuration I've been using for years only fails when I update KDE.

I found some related issue at https://codereview.qt-project.org/c/qt/qtbase/+/494754

And I warned about this issue in 2021 ... no one ask about. No priority, I guess. https://bugs.kde.org/show_bug.cgi?id=445272

Even I wrote in another thread about with or without using PAC files, when trying to download plasmoids, new themes or any other “downloadable” (I suspect using FTP protocol) packages from Plasma settings menus, it simply fails, cause maybe Plasma try to access to proxy without authentication (and it’s required).

Can you attach your .config/kioslaverc file?

(In reply to Nicolas Fella from comment #9)
> Can you attach your .config/kioslaverc file?

Of course. I changed to publish here user/domain and path to PAC file for privacy, but they are correct.

AutoResume=true
ConnectTimeout=20
MarkPartial=true
ProxyConnectTimeout=10
ProxyUrlDisplayFlags=3
ReadTimeout=15
ResponseTimeout=600

[Browser Settings/SMBro]
Password=0H@0GA0H@0AO0I50F>0F>0F:0F=
User=1234@intranet

[Proxy Settings]
NoProxyFor=NO_PROXY
Proxy Config Script=/home/myuser/proxy_PAC_configuracion.pac
ProxyType=2
ReversedException=false
ftpProxy=
httpProxy=http_proxy
httpsProxy=https_proxy
socksProxy=

-----------------
Now that I see this file content, I should add that every time I access an SMB folder in the domain, it forces me to type the user as "1234@intranet", although by default only "1234" appears in the user/password window that appears when trying to access a shared SMB folder. A couple of years ago, that wasn't the case. There was no need to enter the domain. Since some change, it forces me to try "1234@intranet" or "intranet\1234".

If you need more info, please, tell it to me.

What happens when you replace /home/myuser/proxy_PAC_configuracion.pac with file:///home/myuser/proxy_PAC_configuracion.pac in the UI (or the config file directly)?

Before answering the result of the test you ask me, I have verified what is different between the "kioslaverc" files in a "Plasma pre-6" installation (to call it somehow) and "Plasma 6" (I don't know if it is a certain time or a certain version of Plasma 6 when the problem appears).
In that file, there are only two lines that change:
ProxyConnectTimeout=10 (line that doesn't appear in Plasma pre-6)
ftpProxy=NO_PROXY

About ftpProxy value, seems no difference of using NO_PROXY value or not.
In Plasma pre-6, value is EMPTY and works.  In Plasma 6, default value is NO_PROXY.
In Plasma 6, if value is EMPTY then Dolphin shows "Can't connect to host 10.162.0.46: Invalid proxy type for this operaton" when trying reach FTP (I insist, local FTP servers in our intranet) and Dolphin shows "Canceled" when trying to access remote FTP.

Regarding changing the value of "Proxy Config Script", there has been no success after changing the value, logging out and logging back in. Dolphin still behaves the same. Moreover, if I make the change in the Plasma proxy configurator, apply the changes, and open the Plasma proxy configurator again, it doesn't save the change!!! (it probably doesn't recognise the "file" URL as correct). 
Also, I was surprised that if I make the change in the "kioslaverc" file as I had to do because of the problem I just mentioned, and I open the Plasma proxy configurator, it still shows the correct path "/home/...". !!. It is as if that file is not the one that modifies the Plasma proxy configurator.

In any case, after modifying it by hand, logging out, etc, nothing has changed, the problem is still the same.

I