Glass mode agent window crashes renderer process with Tooltip infinite render loop (v3.5.17)

[Juan_Casaus]

Where does the bug appear (feature/product)?

Somewhere else…

Describe the Bug

Title: Glass mode agent window crashes renderer process with Tooltip infinite render loop (v3.5.17)

OS: macOS 25.5.0 (Apple Silicon)

Severity: Frequent — renderer crashes within 15–30 minutes of active use in glass mode

Description

After updating to 3.5.17, the agent window (glass mode) crashes repeatedly. The pattern escalates in three stages:

The CodeWindow goes unresponsive for 5–8 seconds, then recovers. Extension hosts exit cleanly (code 0) and restart.
The cycle repeats every 2–3 minutes during active agent sessions.
Eventually the renderer process is killed by the OS entirely.
The final crash log entry:

CodeWindow: renderer process gone (reason: crashed, code: 5)
Stack trace (from crash)

The unresponsive samples consistently point to a Tooltip component stuck in an infinite React render loop:

at useEffectEvent (workbench.desktop.main.js:603:6614)
at useHover (workbench.desktop.main.js:603:28986)
at Tooltip (workbench.desktop.main.js:631:32755)
…
at useEffectEvent (workbench.desktop.main.js:603:6591)
at useDismiss (workbench.desktop.main.js:603:46286)
at Tooltip (workbench.desktop.main.js:631:32797)
…
at MenuProvider (workbench.desktop.main.js:631:43596)
The same frame (Tooltip → useHover/useDismiss → React reconciler) appears in every unresponsive sample across multiple crash events. The renderer eventually OOMs from the continuous allocation in the loop.

Additional context

This did not happen on 3.4.20 (the previous version before auto-update)
The issue is specific to glass mode — the CursorExtensionIsolationService log confirms the crash windows are all running effective isolation is disabled (forced disabled in glass mode)
The McpProcess and extension hosts are healthy — they restart cleanly after each crash
Memory is not the root cause — the machine has 18GB RAM and had 700MB+ free at crash time

Steps to Reproduce

Reproduction steps

Open a workspace in glass mode (the new 3.5.17 agent panel UI)
Start an active agent session involving multiple tool calls (shell commands, file reads, MCP tool calls)
Keep the session running for 5–10 minutes
The window will go unresponsive within 2–3 minutes; after 15–30 minutes the renderer process crashes
Hovering over elements in the agent panel appears to trigger additional Tooltip renders and accelerates the crash.

Expected Behavior

Additional context

This did not happen on 3.4.20 (the previous version before auto-update)
The issue is specific to glass mode — the CursorExtensionIsolationService log confirms the crash windows are all running effective isolation is disabled (forced disabled in glass mode)
The McpProcess and extension hosts are healthy — they restart cleanly after each crash
Memory is not the root cause — the machine has 18GB RAM and had 700MB+ free at crash time

Screenshots / Screen Recordings

Operating System

MacOS

Version Information

Version: 3.5.17 (darwin-universal)

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

[mohitjain (Mohit)]

This is a known bug with the Glass mode agent window. The crash pattern you’re seeing (the Tooltip render cycle leading to renderer OOM, code 5) matches an issue our team is aware of and tracking.

A partial fix was shipped recently, but as you’ve confirmed, it didn’t fully resolve the problem. Your detail about hovering accelerating the crash is helpful and consistent with what we’re seeing internally.

As a temporary workaround: minimize hovering over UI elements in the agent panel during long sessions. This won’t prevent the crash entirely but may extend the time before it occurs. If you hit the crash, reopening the window with “New Window” will restore your session.

Thank you for the detailed stack trace and reproduction steps — they help our engineering team zero in on the root cause.