# Connection failed after update to latest version

**URL:** <https://forum.cursor.com/t/connection-failed-after-update-to-latest-version/147548>\
**Category:** Bug Reports\
**Created:** [December 28, 2025, 7:34pm UTC](https://forum.cursor.com/t/connection-failed-after-update-to-latest-version/147548 "2025-12-28T19:34:58Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Rejdok](https://avatars.discourse-cdn.com/v4/letter/r/8491ac/32.png) [@Rejdok](https://forum.cursor.com/u/Rejdok)\
**Post date:** [December 28, 2025, 7:34pm UTC](https://forum.cursor.com/t/connection-failed-after-update-to-latest-version/147548/1 "2025-12-28T19:34:58Z")

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### Where does the bug appear (feature/product)?

Cursor IDE

### Describe the Bug

I updated to version 2.3.9 from version 2.1 and started getting errors like “Connection failed. If the problem persists, please check your internet connection or VPN” at around 30-40% context usage.  
If I roll back to version 2.1, the problem goes away.

### Steps to Reproduce

Install lataset version and start using agent mode. Fill context to 30-40%.

### Expected Behavior

Error doesn’t happens

### Operating System

Windows 10/11

### Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.3.9 (system setup)  
VSCode Version: 1.105.1  
Commit: eecab7538820b6470389330d2cca30b703322290  
Date: 2025-12-28T15:39:20.081Z  
Electron: 37.7.0  
Chromium: 138.0.7204.251  
Node.js: 22.20.0  
V8: 13.8.258.32-electron.0  
OS: Windows\_NT x64 10.0.26100

### Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

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<div class="post-metadata">

**Author:** ![deanrie](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/deanrie/32/1263_2.png) [@deanrie](https://forum.cursor.com/u/deanrie)\
**Post date:** [December 29, 2025, 6:37am UTC](https://forum.cursor.com/t/connection-failed-after-update-to-latest-version/147548/2 "2025-12-29T06:37:39Z")

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Hey, thanks for the report. This looks like an interesting issue, a regression between versions 2.1 and 2.3.9.

To dig in, could you share some diagnostic info?

1. Run Network Diagnostics: Cursor Settings \> Network \> Run Diagnostics, then share the results.
2. When the next error happens, copy the Request ID: chat menu (top right) \> Copy Request ID.
3. Open the Developer Tools Console (Help \> Toggle Developer Tools) and check if any errors show up when the issue happens.
4. Which model are you using in Agent Mode?
5. Are you using a VPN, proxy, or a corporate network?

Also, as a temporary workaround, try disabling HTTP/2: App Settings `Ctrl+,` \> search for “HTTP/2” \> enable “Disable HTTP/2”.

Let me know if that helps.

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**Author:** ![system](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/system/32/99069_2.png) [@system](https://forum.cursor.com/u/system)\
**Post date:** [January 20, 2026, 6:38am UTC](https://forum.cursor.com/t/connection-failed-after-update-to-latest-version/147548/3 "2026-01-20T06:38:06Z")

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Closed on January 20, 2026, 6:38am UTC

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