## Describe the bug The **GitHub Copilot for Xcode host app** becomes unresponsive shortly after launch. In Activity Monitor it shows as **Not Responding** (red). While the app window can open, the UI is effectively dead: - **Settings → GitHub Account** stays on "loading…" indefinitely - **Settings → Permissions** stays on "loading…" indefinitely - **Chat window** does not open - **Menu bar icon** does not respond to clicks The Extension Service and Communication Bridge processes start and sometimes connect (feature flags / policy updates appear in logs), but the host app UI never becomes functional. The failure has persisted for several weeks across multiple Copilot versions and after a full clean reinstall. ## Versions - Copilot for Xcode: **0.51.0** (also reproduced on **0.50.0** and **0.42.0**) - Xcode: **26.5** (Build 17F42) - macOS: **26.5.2** (Build 25F84) - Hardware: **MacBook Pro, Apple M5 Pro, 24 GB RAM** ## Steps to reproduce 1. Install GitHub Copilot for Xcode in `/Applications/GitHub Copilot for Xcode.app` 2. Grant required permissions: - Accessibility - App Background Activity (Login Items) - Xcode Source Editor Extension 3. Launch Xcode and open a Swift file 4. Launch **GitHub Copilot for Xcode** (host app) 5. Observe in Activity Monitor: host app goes **Not Responding** within ~30–60 seconds 6. Open Settings → Account / Permissions → stuck on loading 7. Try opening Chat or clicking the menu bar icon → no response ## Expected behavior Settings should load account status and permissions. Chat and menu bar should be usable. ## Actual behavior Host app freezes. Settings spin forever. Chat and menu bar are unresponsive. Representative errors (repeated across sessions): [error] [Client] Failed to update feature flags: Waiting for service to connect to the communication bridge. [info] [Client] XPCService interrupted [error] [UI] Failed to reload status. Connection to extension service error: Couldn't communicate with a helper application. [error] [Client] AgentModeDropdown: Failed to load modes: Connection to extension service error: Couldn't communicate with a helper application. [error] [Service] Failed to connect to bridge (1 consecutive failures): The operation couldn't be completed. (Swift.CancellationError error 1.) [error] [Service] AXObserver: Accessibility API disabled, will try again later On some launches the bridge appears to connect successfully: [info] [CommunicationBridge] Service app found: ... Optional("com.github.CopilotForXcode.ExtensionService") [info] [CommunicationBridge] Service app is still valid [info] [Client] Feature flags updated: agentMode=true, byok=true, mcp=true, editorPreview=true [info] [Client] Copilot policy updated: customAgent=true, mcp=true, subagent=true …but the host app UI remains frozen regardless. ## Troubleshooting already tried - [x] App installed in `/Applications` (not a custom path) - [x] Official uninstall script + delete `~/.config/github-copilot/` + reinstall from DMG - [x] Tested **0.42.0**, **0.50.0**, and **0.51.0** — same behavior on all three - [x] Full Mac reboot after reinstall / upgrade - [x] Force-quit all Copilot processes and relaunch - [x] Verified Accessibility, Background Activity, and Xcode Source Editor Extension permissions - [x] Disabled **Proxy strict SSL** (`GitHubCopilotUseStrictSSL = false`) - [x] Reset TCC permissions for Copilot bundle IDs and re-granted manually After clean reinstalls, `~/.config/github-copilot/auth.db` is empty (0 bytes), so no OAuth session persists — but the UI freeze happens even before sign-in can complete. ## Related issues - #731 — Settings stuck on "account loading" (similar UI symptom; workaround was moving app to `/Applications`, which does not apply here) - #746 — Host app Not Responding on versions > 0.42 (similar symptom, but on **macOS 15.7.3 / Intel**; downgrading to 0.42 worked for that reporter — it does **not** work for me) ## Additional context - Issue started several weeks ago and has been reproducible consistently since. - Antivirus (Avast) and VPN clients are installed but were previously used without issues; Copilot worked fine before this regression. - This appears to be specific to the **macOS 26.5 + Xcode 26.5** environment, since downgrading Copilot and full reinstalls do not help.