Invalid proxy targeted by SonarLint IntelliJ

The problem seems to be related to the proxy. It seems the SonarLint plugin does not honor the proxy setting of the JetBrains IDE and neither seems to be the JetBrains plugin module. We use a company proxy here, which is specified as “”. However, this proxy needs an NTLM authentication which JetBrains does not provide. So I have the “px” proxy running on my machine which translates “normal” proxy requests to NTLM proxy requests. This px proxy works fine. Using e.g. “curl” with this proxy works as expected. I configured my local “px” proxy as the proxy in the IDE’s settings under “Appearance & Behaviour/System Settings/HTTP Proxy”. There I specified “Manual proxy configuration/Host name: number: 3128”.

In the Idea.log I see a lot of messages of the form "Unable to tunnel through proxy. Proxy returns “HTTP/1.1 401 Proxy server authentication failed:”. This is the message our proxy sends when no NTLM authentication is used. I.e. the proxy configuration of the JetBrains IDE was not used.


Hello @dbs_fs ,

Could you please clarify whether the “HTTP/1.1 401 Proxy server authentication failed:” log message you see in the idea.log comes from JetBrainsIDE or from SonarLint (see how to get verbose output in SonarLint)?

Firstly it would be great to confirm that requests not coming from SonarlInt but from JetBrains IDE go through the proxy which was set up as expected (you could use WireShark or a similar tool for that).
If that is the case, then we expect the SonarLint extension to respect the proxy settings that JetBrains IDE has and it would be great if you could share the verbose logs from SonarLint with us to help understand what might be going on.

Also, what version of SonarLint are you using?


Vojtech from :sonarlint:

1 Like

Hello, Vojtech, most of them are from the JetBrains marketplace, but one was not:

SEVERE - #c.i.o.a.i.ApplicationImpl - Unable to tunnel through proxy. Proxy returns "HTTP/1.1 401 Proxy server authentication failed:"

The plugin version was BTW, this version had no way of specifying a SonarLint log. There where no entries Analysis logs and Verbose log in the three dots menu, so it was impossible to get the SonarLint logs. The current version does have these menu entries.

Since I use the newest plugin the error message does no more show up in the log. Maybe this was a glitch. The topic can probably be closed.

Thanks for your help.


Thank you for the update @dbs_fs , glad to hear that updating to the latest version has helped.

All the best,


This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.