Claude Code VS Code extension crashes every 1-2 min with exit code 3 on Windows ARM64 since v2.1.47

Bug Description

Claude Code VS Code extension crashes every 1-2 minutes with exit code 3 (ProcessTransport is not ready) since updating to v2.1.47 on Feb 19, 2026. The same setup worked perfectly for 4-5 months prior to this update.

The extension host becomes unresponsive, VS Code's watchdog kills it, and the user sees:

Error: Claude Code process exited with code 3
View output logs · Troubleshooting resources

Environment

• Extension version: 2.1.47 → auto-updated to 2.1.49 (problem persists)
• Platform: Windows 11 ARM64 (10.0.26200)
• RAM: 16 GB
• VS Code: Latest stable
• Architecture: ARM64 (win32-arm64)

Timeline

| Date | Event |
|------|-------|
| Oct 2025 – Feb 18, 2026 | Extension worked perfectly for ~4-5 months |
| Feb 19, 07:41 | Claude Code v2.1.47 installed — problems begin immediately |
| Feb 19, 15:30 | First ProcessTransport is not ready error |
| Feb 19, 15:58 | Extension flagged as cause — 28% CPU |
| Feb 19, 17:37 | Claude Code takes 100% CPU → extension host unresponsive |
| Feb 20 | Auto-updated to v2.1.49 — problem continues |
| Feb 22 | Exit code 3 crashes start happening every 2-8 minutes |
| Feb 23 | Crashes every 1-2 minutes, making the extension unusable |

Key Observations

• claude.exe memory usage: 509-578 MB for a single process — this seems excessive
• Stale IDE lock files accumulate: Found 8 orphaned .lock files in ~/.claude/ide/ from crashed sessions that never cleaned up
• Project size: ~1.4 GB total (943 MB node_modules), ~500 source files — not unusually large
• Debug logs show rapid stream processing restarts consistent with the process being killed and restarting repeatedly

What I've Tried (none resolved the issue)

1. ✅ Disabled GitHub Copilot Chat extension
2. ✅ Disabled GitHub Copilot extension
3. ✅ Disabled Deno extension
4. ✅ Disabled remote container extensions
5. ✅ Cleaned stale IDE lock files from ~/.claude/ide/
6. ✅ Added .claudeignore to reduce indexed files
7. ✅ Restarted VS Code multiple times
8. ✅ Extension auto-updated from 2.1.47 to 2.1.49 — no improvement

Reproduction Steps

1. Install Claude Code v2.1.49 on Windows 11 ARM64 with 16 GB RAM
2. Open a Next.js project (~500 source files)
3. Use the extension normally
4. Within 1-2 minutes, the extension crashes with exit code 3
5. It restarts automatically and crashes again in 1-2 minutes
6. This cycle repeats indefinitely

Expected Behavior

The extension should remain stable during normal use, as it did for 4-5 months on this exact same hardware and project prior to the v2.1.47 update.

Debug Log Excerpt

[DEBUG] [Query.streamInput] Starting to process input stream
[DEBUG] [Query.streamInput] Processing message 1: user
[DEBUG] [Query.streamInput] Finished processing 1 messages from input stream
[DEBUG] [Query.streamInput] Has bidirectional needs, waiting for first result
[DEBUG] [Query.waitForFirstResult] Result already received, returning immediately
[DEBUG] [Query] Calling transport.endInput() to close stdin to CLI process

This pattern repeats every 1-2 minutes as the process crashes and restarts.

Impact

This is a complete blocker — the extension is unusable. Project work has been on hold for 4 days. A previous issue was filed but received no response.