Slow Context Summary, up to 10min wait

[KevinLourd]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

When Claude Sonnet 4.5 needs to create a context summary, it seems to freeze on Planning next moves for ages. He only does that when context is full. After 5-10min generally, it says Contextext summarized and then continues normally

Steps to Reproduce

Normal usage

Expected Behavior

Fast
Should say ‘Summarizing context…’, and be like 10s-long max

Screenshots / Screen Recordings

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.1.46
VSCode Version: 1.105.1
Commit: ab326d0767c02fb9847b342c43ea58275c4b1680
Date: 2025-12-02T03:59:29.283Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 23.5.0

For AI issues: which model did you use?

Claude Sonnet 4.5

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

[deanrie]

Hey, thanks for the report.

There’s a related bug we’re already tracking:

• Main thread: The Cursor IDE freezes at the "planning next moves" stage
• Similar cases: Planning next moves stuck, Cursor is unresponsive after sending a prompt to plan

To link your case, please share:

• 2-3 Request IDs captured during the long wait
• A screenshot of Settings - Network - Run Diagnostics
• Indexing & Docs status for your project and for a small empty folder - screenshots
• Whether this helps: Settings - search “HTTP/2” - enable “Disable HTTP/2” - restart
• Behavior on other models (e.g., Composer 1, Haiku 4.5, Opus 4.5) compared to Sonnet 4.5
• Errors from Help - Toggle Developer Tools - Console during the wait

Quick checks:

• In a new chat, run /summarize until context is summarized: Summarization | Cursor Docs
• Try the same request in a small repo or an empty folder - compare time to “Context summarized”

Once you share the details, I’ll add them to the ticket.

[KevinLourd]

• 2-3 Request IDs captured during the long wait

a25aa7c7-e6fa-4b9e-a771-05061575c024
920e6559-5466-44b7-a04c-45d911d77■■■
0181cc74-793f-4e4a-911c-b737e41c1d24

A screenshot of Settings - Network - Run Diagnostics

Indexing & Docs status for your project and for a small empty folder - screenshots
I dont understand the question

Whether this helps: Settings - search “HTTP/2” - enable “Disable HTTP/2” - restart
→ Doesn’t help

Behavior on other models (e.g., Composer 1, Haiku 4.5, Opus 4.5) compared to Sonnet 4.5
→ Composer 1, Opus 4.5, Gemini 3 Pro : same

Errors from Help - Toggle Developer Tools - Console during the wait

Errors: 4

Infinite warning loop

[deanrie]

Thanks for the data. From the DIAG and console, it’s an HTTP/2 network error - NGHTTP2_REFUSED_STREAM. A few steps to narrow it down:

1. In settings.json, force set:
   "cursor.general.disableHttp2": true
   Fully exit Cursor and restart. Check chat and network diagnostics.

2. Test without VPN/proxy. If using Zscaler/Cloudflare WARP or corporate filter - temporarily disable or add exception and retry. Best - test via mobile hotspot.

3. To check summarization, try /summarize in a new chat and empty folder - compare time to “Context summarized”. Docs: Summarization | Cursor Docs

Let me know the results.