Agent just freezes mid process

AndrewC · October 27, 2025, 1:06pm

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Im having to enter “resume” the whole time to get the Agent to keep working.

It just stalls midway through its deliberations.

Mostly use AUTO, but tried some other models too.

Steps to Reproduce

In Cursor send requests to AI Agent

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.7.54 (user setup)
VSCode Version: 1.99.3
Commit: 5c17eb2968a37f66bc6662f48d6356a100b67be0
Date: 2025-10-21T19:07:38.476Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Windows_NT x64 10.0.19045

For AI issues: which model did you use?

AUTO, claude-4.5

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

arrold · October 27, 2025, 2:22pm

Yeah I’m seeing some general things happen like this, first noticed it on macbook on version 1.7.54, also saw it on arch linux . rolled back to 1.7.46 and was still happening. This morning I tried 2.0.11 but that didn’t seem any better…so maybe it’s not a version thing.

Doesn’t seem specific to any particular operation, it’s happened when it’s just thinking, trying to run terminal commands or editing files

TomerM · October 27, 2025, 3:12pm

Hi Cursor team, I’ve seen quite a few threads describing similar issues, and I’m experiencing the same. Cursor has been very difficult to work with over the past few days, regardless of the underlying cause.

Could you please provide an update or a solution? I’m really on the edge of giving up on the platform.

AndrewC · October 27, 2025, 3:33pm

Cursor needs to at least have a feature that it can resume itself when the AI is stalling. Just stopping mid reply or throwing a connection error VPN whatever is not good enough

deanrie · October 27, 2025, 5:20pm

Hey, thanks for the report. Several users have recently seen the Agent pause during work.

Please help us debug:

Open Developer Tools with Ctrl+Shift+I → Console
Reproduce the stalling issue
Share any errors or warnings that appear

Also, does this happen more with specific operations (terminal commands, file edits, etc)?

Koptan · October 27, 2025, 6:29pm

vscode-app-1761589637530.txt (125.9 KB)

I am having the same issue, I am using :

Version: 1.7.54
VSCode Version: 1.99.3
Commit: 5c17eb2968a37f66bc6662f48d6356a100b67be0
Date: 2025-10-21T19:07:38.476Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Linux x64 6.8.0-86-generic

Please check the log file in the attachment.

AndrewC · October 29, 2025, 8:40am

@deanrie
ERR [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools: ConnectError: [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools
at vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:7337:373472 ConnectError: [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools
at workbench.desktop.main.js:7337:373472Caused by: Error: invalid int 32: 4294967295
at Rsn (workbench.desktop.main.js:440:32595)
at dqo.int32 (workbench.desktop.main.js:441:12763)
at MPt (workbench.desktop.main.js:441:19797)
at fqo (workbench.desktop.main.js:441:18900)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at fZt.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at WYt.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at nni.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18980)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at Zii.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18980)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at Eii.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at iii.toBinary (workbench.desktop.main.js:440:34638)
at workbench.desktop.main.js:7337:373443
error @ workbench.desktop.main.js:55
error @ workbench.desktop.main.js:55
error @ workbench.desktop.main.js:9359
handleUnexpectedError @ workbench.desktop.main.js:9356
(anonymous) @ workbench.desktop.main.js:9356
onUnexpectedError @ workbench.desktop.main.js:27
la @ workbench.desktop.main.js:22
(anonymous) @ workbench.desktop.main.js:9356
workbench.desktop.main.js:5250 [composer] ToolFormer: error in toolWrappedStream undefined
toolWrappedStream @ workbench.desktop.main.js:5250
await in toolWrappedStream
(anonymous) @ workbench.desktop.main.js:6358
handleStreamComposer @ workbench.desktop.main.js:3445
streamResponse @ workbench.desktop.main.js:7900
await in streamResponse
(anonymous) @ workbench.desktop.main.js:7961
(anonymous) @ workbench.desktop.main.js:7963
(anonymous) @ workbench.desktop.main.js:7954
(anonymous) @ workbench.desktop.main.js:7957
(anonymous) @ workbench.desktop.main.js:7957
(anonymous) @ workbench.desktop.main.js:5250
(anonymous) @ workbench.desktop.main.js:7961
processCodeBlocks @ workbench.desktop.main.js:3486
submitChatMaybeAbortCurrent @ workbench.desktop.main.js:6358
await in submitChatMaybeAbortCurrent
(anonymous) @ workbench.desktop.main.js:52
rvs @ workbench.desktop.main.js:52
Dxu @ workbench.desktop.main.js:52
n.value @ workbench.desktop.main.js:52
re @ workbench.desktop.main.js:6348
onClick @ workbench.desktop.main.js:7195
(anonymous) @ workbench.desktop.main.js:3510
workbench.desktop.main.js:7900 [AiService] streamResponse ConnectError: [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools
at workbench.desktop.main.js:7337:373472Caused by: Error: invalid int 32: 4294967295
at Rsn (workbench.desktop.main.js:440:32595)
at dqo.int32 (workbench.desktop.main.js:441:12763)
at MPt (workbench.desktop.main.js:441:19797)
at fqo (workbench.desktop.main.js:441:18900)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at fZt.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at WYt.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at nni.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18980)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at Zii.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18980)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at Eii.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at iii.toBinary (workbench.desktop.main.js:440:34638)
at workbench.desktop.main.js:7337:373443
streamResponse @ workbench.desktop.main.js:7900
await in streamResponse
(anonymous) @ workbench.desktop.main.js:7961
(anonymous) @ workbench.desktop.main.js:7963
(anonymous) @ workbench.desktop.main.js:7954
(anonymous) @ workbench.desktop.main.js:7957
(anonymous) @ workbench.desktop.main.js:7957
(anonymous) @ workbench.desktop.main.js:5250
(anonymous) @ workbench.desktop.main.js:7961
processCodeBlocks @ workbench.desktop.main.js:3486
submitChatMaybeAbortCurrent @ workbench.desktop.main.js:6358
await in submitChatMaybeAbortCurrent
(anonymous) @ workbench.desktop.main.js:52
rvs @ workbench.desktop.main.js:52
Dxu @ workbench.desktop.main.js:52
n.value @ workbench.desktop.main.js:52
re @ workbench.desktop.main.js:6348
onClick @ workbench.desktop.main.js:7195
(anonymous) @ workbench.desktop.main.js:3510
workbench.desktop.main.js:6359 [composer] Error in AI response: undefined ConnectError: [internal] Serialization error in aiserver.v1.StreamUnifiedChatRequestWithTools
at workbench.desktop.main.js:7337:373472Caused by: Error: invalid int 32: 4294967295
at Rsn (workbench.desktop.main.js:440:32595)
at dqo.int32 (workbench.desktop.main.js:441:12763)
at MPt (workbench.desktop.main.js:441:19797)
at fqo (workbench.desktop.main.js:441:18900)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at fZt.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at WYt.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at nni.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18980)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at Zii.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18980)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at Eii.toBinary (workbench.desktop.main.js:440:34638)
at pqo (workbench.desktop.main.js:441:19718)
at fqo (workbench.desktop.main.js:441:18998)
at Object.writeMessage (workbench.desktop.main.js:441:16664)
at iii.toBinary (workbench.desktop.main.js:440:34638)
at workbench.desktop.main.js:7337:373443
submitChatMaybeAbortCurrent @ workbench.desktop.main.js:6359
await in submitChatMaybeAbortCurrent
(anonymous) @ workbench.desktop.main.js:52
rvs @ workbench.desktop.main.js:52
Dxu @ workbench.desktop.main.js:52
n.value @ workbench.desktop.main.js:52
re @ workbench.desktop.main.js:6348
onClick @ workbench.desktop.main.js:7195
(anonymous) @ workbench.desktop.main.js:3510
workbench.desktop.main.js:6359 [composer] Failed to get complete AI response
submitChatMaybeAbortCurrent @ workbench.desktop.main.js:6359
await in submitChatMaybeAbortCurrent
(anonymous) @ workbench.desktop.main.js:52
rvs @ workbench.desktop.main.js:52
Dxu @ workbench.desktop.main.js:52
n.value @ workbench.desktop.main.js:52
re @ workbench.desktop.main.js:6348
onClick @ workbench.desktop.main.js:7195
(anonymous) @ workbench.desktop.main.js:3510

deanrie · October 29, 2025, 1:26pm

This is a separate long‑standing issue that happens when the Agent tries to serialize very large payloads (long terminal outputs, large responses, etc.). Unfortunately, there’s no official fix yet, but these workarounds help:

Start a new chat when it happens
Limit command output in your .cursorrules
Avoid operations that generate very verbose terminal output

Tracker: Serialization error

therickfactr · November 3, 2025, 10:45am

Deanrie: You’re kidding, right?

This problem happens both regularly and randomly. I believe it’s being reported here on Windows, but it’s also happening on macOs.

This “debugging procedure” for users is silly. It’s time-consuming an obtuse. The likelihood that it will happen while I have the Developer Tools open is unlikely.

Note that this happens MOSTLY when the Agent is running a terminal command. One sees the command emitted by the agent and then… nothing… the agent just never responds again. I can interrupt it by forcing another prompt. I usually ask it, “Are you stuck?” and the response is “No, I’m not stuck I’m just waiting for <whatever_command_it_was_running> to finish. There is a timing/synchronization problem between the Agent and the command shell. I’ve seen it happen MORE with PowerShell than with bash, but it happens with both.

I am running on a Mac. See full info below. It is inexplicable to me how you guys can’t repro this. Are you not dog-fooding your own product?

My setup:

MacBook Pro 16-inch, Nov 2024
Chip: Apple M4 Max
Memory: 64GB
Startup disk: Macintosh HD (1.6TB of 2TB available).
macOS: Tahoe 26.0.1

I’m a Pro+ subscriber who uses Cursor 6-7 days a week for 10-12 hours. Sometimes my use is very, very intense (lots of requests while refactoring multiple projects).

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