Very frequently facing vpn issue

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Network tests passes for all!!

Very frequently facing this issue where connection error display, I am unable to work, tried restart cursor, machine but doesn’t work.

2025-12-29 18:13:03.642 [error] [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools: ConnectError: [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools
at vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:12375:452121 [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools

Steps to Reproduce

Reprocution is intermittent, but once it comes it sticks

Expected Behavior

Cursor should work.

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.2.44 (system setup)
VSCode Version: 1.105.1
Commit: 20adc1003928b0f1b99305dbaf845656ff81f5d0
Date: 2025-12-24T21:41:47.598Z (4 days ago)
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

For AI issues: add Request ID with privacy disabled

Request ID: a305fb26-1a4f-4191-ba48-c1df955e2493
ConnectError: [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools
at vscode-file://vscode-app/c:/Program%20Files/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:12375:452121

Does this stop you from using Cursor

Yes - Cursor is unusable

2

Hey, thanks for the report with all the details.

This is a known issue with the serialization error on Windows. The team is already working on a fix. Similar reports:

The root cause is an int32 overflow while serializing terminal output or exit codes. It can show up as a connection error, but it isn’t actually a network issue.

Workaround: When the error happens:

  1. Start a new chat Cmd/Ctrl+T/N
  2. Or restart Cursor

Let me know if the workaround helps.

3

Hi,

Restart doesn’t help.

I need to clear complete cache, it some times help.