# Code Nextflow extension stuck on “Initializing Nextflow language server…” — fixed by disabling fetchAdditionalSupport/systemCertificates

**URL:** <https://community.seqera.io/t/code-nextflow-extension-stuck-on-initializing-nextflow-language-server-fixed-by-disabling-fetchadditionalsupport-systemcertificates/2519>\
**Category:** Ask for help\
**Created:** [January 30, 2026, 2:24am UTC](https://community.seqera.io/t/code-nextflow-extension-stuck-on-initializing-nextflow-language-server-fixed-by-disabling-fetchadditionalsupport-systemcertificates/2519 "2026-01-30T02:24:18Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![michaelgatzen](https://dub1.discourse-cdn.com/flex013/user_avatar/community.seqera.io/michaelgatzen/32/2255_2.png) [@michaelgatzen](https://community.seqera.io/u/michaelgatzen)\
**Post date:** [January 30, 2026, 2:24am UTC](https://community.seqera.io/t/code-nextflow-extension-stuck-on-initializing-nextflow-language-server-fixed-by-disabling-fetchadditionalsupport-systemcertificates/2519/1 "2026-01-30T02:24:18Z")

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(Text generated using generative AI)

Hi all,

I ran into an issue with the VS Code Nextflow extension where it would get stuck indefinitely on:

> _“Initializing Nextflow language server…”_

### Environment

- macOS

- VS Code (recent version)

- Nextflow VS Code extension `nextflow.nextflow` v1.6.1

- Nextflow CLI installed separately (works fine)

- Java 17 installed via Homebrew (`openjdk@17`)

### Symptoms

- The status bar shows _Initializing Nextflow language server…_ and never completes

- No **“Nextflow Language Server”** output channel appears

- Developer Tools console shows repeated errors like:

This happens even when:

- `nextflow.java.home` is explicitly set

- The language server JAR is pre-downloaded and `nextflow.languageVersion` is pinned

### Root cause (likely)

This appears to be a VS Code extension host networking issue related to Node’s `fetch` + certificate handling on macOS. The failure occurs before the language server actually starts.

### Fix / Workaround

Adding the following settings resolved the issue immediately:

```auto
{
  "http.fetchAdditionalSupport": false,
  "http.systemCertificates": false
}

```

After setting these:

- Reload the window (`Developer: Reload Window`)

- The Nextflow language server starts normally

- Syntax highlighting, validation, etc. work as expected

### Notes

- This is **not** related to the Nextflow CLI or Java installation

- `curl` access to GitHub works fine from the terminal

- The issue seems specific to VS Code’s internal fetch behavior for extensions

Hopefully this helps other users who hit the same silent failure, and gives maintainers a concrete repro + workaround.

Happy to provide more details if useful.