HTTP/2 makes Cursor unusable

[qlive (Clive Lewis)]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

I still getting the “Connection failed. If the problem persists, please check your internet connection or VPN”
I ran Network diagnostics and there is everything fine e2e.
I tried to switch different networks and still getting the same.
Only switching the HTTP protocol to /1.1, /1.0 in Network tab Cursor Settings helps

Steps to Reproduce

Agent chat + HTTP/2

Expected Behavior

“Connection failed. If the problem persists, please check your internet connection or VPN” message

Screenshots / Screen Recordings

Operating System

Linux

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.1.47
VSCode Version: 1.105.1
Commit: 2d3ce3499c15efd55b6b8538ea255eb7ba4266b0
Date: 2025-12-04T02:31:50.567Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Linux x64 6.14.0-36-generic

For AI issues: which model did you use?

Auto but it happens with every model

For AI issues: add Request ID with privacy disabled

Request ID: 0d1ff565-f1df-411b-bbe7-6174b5a462ab
ConnectError: [internal] 49495203907776:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

at isu.$streamAiConnect (vscode-file://vscode-app/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:6409:406134)
at async vscode-file://vscode-app/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:565:80844
at async Object.run (vscode-file://vscode-app/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:6477:42602)
at async o (vscode-file://vscode-app/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:2815:1269)
at async Promise.allSettled (index 0)
at async fHr.run (vscode-file://vscode-app/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:2815:6513)

Does this stop you from using Cursor

Yes - Cursor is unusable

[deanrie]

Hey, thanks for the report. This is a known issue on some networks with HTTP/2.

What you can do now:

• Keep HTTP/2 disabled: App Settings CTRL+, → search “HTTP/2” → enable “Disable HTTP/2”. Details and confirmation of the fix: Connection failed. If the problem persists, please check your internet connection or VPN - #4 by Worry

To help us dig deeper, please share:

• Screenshot of Settings → Network → Run Diagnostics
• Network type: VPN/proxy/corporate network, whether Zscaler/Cloudflare/TLS-intercept is present
• Behavior on another network without VPN/proxy
• Console errors from Help → Toggle Developer Tools
• New Request IDs from failed requests

Docs for common issues: Common Issues | Cursor Docs

Let me know if keeping HTTP/2 disabled is stable. I’ll forward the case to the team once I have these details.

[Kirow]

I can see same problem on my environment. And I have it multiple times already.

Skipping all the steps…
If I remove User/workspaceStorage/<workspace>/state.vscdb from user’s folder - it start working again, but I loosing all my project chat history. So there is something in ItemTable that prevent HTTP/2 from running. I have not find it yet, but it’s there. And it has nothing with network config.

So currently 2 solutions:

• switch to HTTP/1.1
• reset chat history (remove state.vscdb)

But I want to use HTTP/2 and have my chat history in place.

UPD: Actually issue reproduced every time when I create 2nd agent chat, If I remove all chats - first one will work, 2nd will not.

[Winstarshl]

Cursor V2 HTTP/2 TLS handshake failure to api2.cursor.sh (boringssl alert 40)

Hi Cursor team,

Cursor V2 fails to connect to api2.cursor.sh when using HTTP/2: Network Diagnostics shows SSLV3_ALERT_HANDSHAKE_FAILURE (boringssl, alert number 40) for API/Ping/Chat/Agent. Cursor V1.1 works fine.

Environment:

• macOS (darwin 25.1.0), no proxy/VPN.
• System proxies disabled (scutil --proxy, networksetup -getwebproxy/-getsecurewebproxy/-getautoproxyurl → Disabled).
• TLS from system is fine:
  • openssl s_client -connect api2.cursor.sh:443 -servername api2.cursor.sh → OK (TLS 1.3, GTS Root R4).
  • curl -I --http2 https://api2.cursor.sh → HTTP/2 200 OK.
  • node -e “require(‘https’).get(‘https://api2.cursor.sh’, …)” → status 200.

Behavior:

• In Cursor V2 with HTTP/2 (default) Diagnostics are red with SSL handshake failure.
• Switching Network → HTTP Compatibility Mode = HTTP/1.1 fixes everything.

Expectation:

• HTTP/2 should work in V2 without handshake errors, or provide a flag/workaround in the network stack (boringssl/h2).

Also I from Ukraine

[mmatiush (Max)]

Please prioritize the bugfix. It really is a pain.

I’ve noticed a lot of similar reports on the forum.

Request ID: a75ca96e-7c6e-48f2-bbab-33fd992c280d
ConnectError: [internal] 1151053741376:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

at cGc.$streamAiConnect (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:11956:453313)
at async vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:585:94724
at async Object.run (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:12004:10221)
at async o (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:8410:1269)
at async Promise.allSettled (index 0)
at async Ezr.run (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:8410:6561)

[syntaxwanderer (Taras Hanych)]

This helped in my case - but it’s complete amnesia. All chats will be lost

rm -rf ~/.config/Cursor ~/.cache/Cursor ~/.cursor

[Jefe]

Same issue.

[qlive (Clive Lewis)]

It seems this is a genuine bug on the Cursor side. Hopefully the team will notice it. I also didn’t use any VPNs or proxies and tried with different networks.

[Kirow]

Ok, seems HTTP/2 start working again. At least for me

[Joonel]

Same issue here. No proxies, VPNs, bridges etc. are used.

Version: 2.2.20 (user setup)
VSCode Version: 1.105.1
Commit: b3573281c4775bfc6bba466bf6563d3d498d1070
Date: 2025-12-12T06:29:26.017Z
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 10.0.26200

[Max_Donchenko]

I can confirm too - the issue is gone (v2.2.20)

[Kirow]

Ok…It does not work again…
And now I see list of errors in diagnostics

[Joonel]

I wonder if Cursor’s new Debug mode can’t handle this issue though? :^))

[Serp]

I have been using HTTP/2 for a month or maybe little bit more than that. Before it was no-go, but now it seems to be working in my case.

Why did I try again? Because network diagnostics showed it had lesser ping than HTTP1.1.

[Max_Donchenko]

I replied in this thread: Connection error in Cursor when on Ukrainian IP
So I’ll duplicate it here that the issue is still relevant as of v2.2.20 (it was gone for one session, but after I relaunched the app, it started happening again).

I ended up installing the older version as suggested in one of the similar threads on this topic. v2.1.42 works for me:

GitHub - oslook/cursor-ai-downloads: All Cursor AI's official download links for both...

[Joonel]

hey @deanrie it’s now clear that 2.1.50 broke the HTTP/2. Can the devs throw the 2.1.42 vs 2.1.50 diff to Gemini 3 Pro and get the thing fixed?))

[Kirow]

For me it seems not related to the app version. Because it stop/start working on the same version. Today HTTP/2 start working again, I did not make any updates.

[sguin3395 (Sitakanta Guin)]

no matter what network I’m on. Nothing seems to be working. It used to work well till yesterday, don’t know what happened.

[Kirow]

Problem returned, and persists for few days already…