Cursor cannot be used: any message I send returns an error

Support Bug Reports
1

Hi Cursor Support Team,

I am currently unable to use Cursor at all. Every time I try to send any message, it returns an error.

1. Problem Description:
I am currently unable to use Cursor at all. Every time I try to send any message, it returns an error.

2. Error Message:

Append data exceeds maximum size of 52428800 bytes

Request ID: a6640044-18ba-477e-b7c5-7253aace66d5
{“error”:“ERROR_BAD_REQUEST”,“details”:{“title”:“Bad Request”,“detail”:“Append data exceeds maximum size of 52428800 bytes”,“isRetryable”:false,“additionalInfo”:{},“buttons”:,“planChoices”:},“isExpected”:true}
Bad Request Append data exceeds maximum size of 52428800 bytes
eqn: Bad Request Append data exceeds maximum size of 52428800 bytes
at hUk (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:36253:27087)
at B4y (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:36253:25971)
at yUk (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:36254:6852)
at DLp.run (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:36254:11720)
at async age.runAgentLoop (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:47602:65127)
at async yvf.streamFromAgentBackend (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:47670:12112)
at async yvf.getAgentStreamResponse (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:47670:19276)
at async Vut.submitChatMaybeAbortCurrent (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:36386:16963)
at async Fs (vscode-file://vscode-app/d:/DevApps/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:46675:3887)

3. Steps to Reproduce:

  1. Open Cursor editor

  2. Open the AI chat box (Cmd+L on Mac / Ctrl+L on Windows/Linux)

  3. Type any message — even a single word like “hello” — and press Enter

  4. The error appears immediately

  5. The same error occurs even when I open an empty folder (no files at all)

    2
    21897×996 51.6 KB

4. My Environment:

  • Version: 3.6.21 (user setup)
    VS Code Extension API: 1.105.1
    Commit: e7a7e93f4d75f8272503ecf33cedbaae10114a10
    Date: 2026-05-28T21:45:36.072Z
    Layout: editor
    Build Type: Stable
    Release Track: Default
    Electron: 39.8.1
    Chromium: 142.0.7444.265
    Node.js: 22.22.1
    V8: 14.2.231.22-electron.0
    xterm.js: 6.1.0-beta.220
    OS: Windows_NT x64 10.0.26200

I have attached screenshots of the error below. Please help me fix this as soon as possible.

Thank you,

4

把http1.1换成http2试试

5

厉害，可以了，感谢大佬

7

Hey, glad it worked. For any user who hits the same Append data exceeds maximum size of 52428800 bytes:

This error shows up when HTTP/2 is disabled. With HTTP/1.1, the payload gets encoded in a way that hits the 50 MB limit faster. The fix, like @m3waver said, is to enable HTTP/2:

App Settings Ctrl + Shift + , > search for HTTP/2 > make sure Disable HTTP/2 is turned off.

Also, I’d recommend updating to the latest version. It includes fixes that remove this limit even without switching HTTP/2.

If it happens again, message me and we’ll take a look.