[Bug]: 3.17.0 Proxy Handling Broken

[funkyaardvark]

⚠️ Before submitting, please verify the following: ⚠️

• This is a bug, not a question or a configuration issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server and Desktop Client are up to date. See Server Maintenance and Release Schedule and Desktop Releases for supported versions.
• I agree to follow Nextcloud's Code of Conduct

Bug description

When using the 3.17.0 desktop client on Ubuntu 24.04 I am unable to add or use accounts in conjunction with SOCKS proxies.

This has been tested with upgrading from 3.16.0 to 3.17.0 and with a fresh desktop installation of 3.17.0 on a Ubuntu 24.04 VM.

Tested versions that do not display the issue are 3.16.0, 3.16.4, and 3.16.6

Steps to reproduce

1a. Fresh install of Ubuntu and newly downloaded AppImage for 3.17.0
2a. Attempt to add account with system proxy (it will fail to connect to the Nextcloud server through the socks proxy with no way to modify the behavior in the GUI until after account is added)

1b. Fresh install of Ubuntu and newly downloaded AppImage for 3.17.0
2b. Attempt to add account with direct network access to Nextcloud server, it will succeed.
3b. Modify user SOCKS proxy settings
4b. Attempt to use SOCKS proxy without direct network access to Nextcloud server, it will fail but settings will persist.
...

Expected behavior

In previous versions it was possible to modify the network settings before adding an account, which is needed to reach the Nextcloud server and sync files in my instance. This can be seen in the following image.

In 3.17.0 that option has been removed and is restricted until an account has been added successfully:

The proxy setting in 3.17.0 is available in individual user settings once one has been added to the desktop client in but does not handle forwarding properly.

Even when an account is added with direct connection to the Nextcloud server with the desktop client 3.17.0 and SOCKS settings are set in the desktop client GUI after an account has been added communication fails on attempting to rely on that SOCKS proxy.

Which files are affected by this bug

desktop client (likely ~/.config/Nextcloud/nextcloud.cfg)

Operating system

Linux

Which version of the operating system you are running.

Ubunto 24.04

Package

Official Linux AppImage

Nextcloud Server version

31.0.7

Nextcloud Desktop Client version

3.17.0

Is this bug present after an update or on a fresh install?

Fresh desktop client install

Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

Are you using an external user-backend?

• Default internal user-backend
• LDAP/ Active Directory
• SSO - SAML
• Other

Nextcloud Server logs

Additional info

When direct access is granted to the Nextcloud server in order to add an account it is added successfully and the SOCKS settings can be changed to the desired configuration. However upon disconnecting and attempting to reconnect over the SOCKS proxy, it will continue to fail despite working in earlier versions of Nextcloud.
It also appears that the default behavior is to use no proxy when an account has been added, I am not sure if this would affect initial or upgrade behavior (This appears to contrast 3.16.6 observed behavior which defaults to system proxy).

Manually adding (or copying old proxy config from 3.16) to the local Nextcloud configuration files also does not change this behavior and it is not possible to add accounts to the desktop client.

[smcgu]

I can confirm that proxy handling is broken in 3.17.0 for Ubuntu packages, too. This affects both SOCKS5 and HTTP(S) proxies. In my case (and across multiple systems), these are running Ubuntu 22.04.

To be clear, this version completely breaks the ability for Nextcloud Desktop to use a proxy connection to a server. So, my systems are unable to:

1. Add accounts
2. Sync connections
3. Establish any kind of connection to a server through a proxy

To replicate:

1. Upgrade from 3.16.4-20250429.181655.0febbee77-1.0~jammy1 to 3.17.0-20250813.142751.55f04ef44-1.0~jammy1
2. Connections no longer work.

This may be related to changes made in PR #8169 by @camilasan and @mgallien. I should note that proxy handling has been partially broken for nearly a year (see #7438). This update completely breaks the ability to use proxy connections.

[smcgu]

It looks like there were some network-related PRs for 3.17, too:

• Removes global network settings #7951
• fix(migration): migrate general network settings. #8228

[smcgu]

Some logs (slightly redacted/modified):

2025-08-15 19:45:41:717 [ info nextcloud.gui.account.state ./src/gui/accountstate.cpp:591 ]:    Checking server availability for account "user123"
2025-08-15 19:45:41:717 [ info nextcloud.sync.accessmanager ./src/libsync/accessmanager.cpp:72 ]:       2 "" "https://nextcloud.internal.example.com/index.php/204" has X-Request-ID "4***"
2025-08-15 19:45:41:717 [ info nextcloud.sync.networkjob ./src/libsync/abstractnetworkjob.cpp:359 ]:    OCC::SimpleNetworkJob created for "https://nextcloud.internal.example.com" + "" ""
2025-08-15 19:45:41:722 [ info nextcloud.sync.credentials.webflow ./src/gui/creds/webflowcredentials.cpp:411 ]: request finished QUrl("https://nextcloud.internal.example.com/index.php/204") with request id "4***"
2025-08-15 19:45:41:722 [ warning nextcloud.sync.networkjob ./src/libsync/abstractnetworkjob.cpp:465 ]: Network request error "Host nextcloud.internal.example.com not found" HTTP status 0 httpReason ""
2025-08-15 19:45:41:722 [ warning nextcloud.sync.networkjob ./src/libsync/abstractnetworkjob.cpp:214 ]: QNetworkReply::HostNotFoundError "An unexpected error occurred. Please try syncing again or contact contact your server administrator if the issue continues." QVariant(Invalid)
2025-08-15 19:45:41:722 [ warning nextcloud.sync.credentials.webflow ./src/gui/creds/webflowcredentials.cpp:212 ]:      QNetworkReply::HostNotFoundError
2025-08-15 19:45:41:722 [ warning nextcloud.sync.credentials.webflow ./src/gui/creds/webflowcredentials.cpp:213 ]:      "Host nextcloud.internal.example.com not found

[camilasan]

2. Connections no longer work.

Do you mean the issue is the same as the original report: in order to connect, the proxy settings need to be loaded before adding an account?

We will investigate it and get back to you.

[smcgu]

2. Connections no longer work.

Do you mean the issue is the same as the original report: in order to connect, the proxy settings need to be loaded before adding an account?

We will investigate it and get back to you.

Proxying is completely broken now and the original workarounds no longer work. I have updated #7438 because the handling of config data across restarts has changed since the original issue submission.

[smcgu]

Here is a more complete log file. If I can find how to enable more verbose logs, I will upload it, too.

20250815_1958_nextcloud.log

[smcgu]

Logfile with logDebug=true.

20250815_2045_nextcloud.log

[smcgu]

The broken proxy handling appears in 3.16.6-20250628.084039.957b27497-1.0~jammy1, so I think this issue title is misleading. I just reverted to 3.16.6 and I am unable to get proxy connections to work. I'll update when I find a version that works. My test system was working with 3.16.4-20250429.181655.0febbee77-1.0~jammy1

[smcgu]

I was able to get proxy configuration/network traffic to work with 3.16.5. Broken versions: 3.16.6 and 3.17.0.