If your Claude Code extension hangs/freezes when running multiple agents, then I feel your pain.
The root cause appears to be multiple claude.exe processes fighting over ~/.claude.json with no file locking. Anthropic knows, the 2.0.61 changelog literally says:
2.0.61
Reverted VSCode support for multiple terminal clients due to responsiveness issues.
They added multi-tab support, claim it broke, and they reverted it. Multiple tabs used to work fine for me before 2.0.61, now newer versions freeze constantly.
Workaround: pin to 2.0.60
Install 2.0.60 from the VSIX and disable auto-update. This is the last version before the multi-client changes landed.
Next problem: 2.0.60 has claude-opus-4-5-20251101 hardcoded and doesn't recognize Opus 4.6.
Fix: patch the binary
Close VS Code completely, then run in PowerShell:
# Back up first
$dir = "$env:USERPROFILE\.vscode\extensions\anthropic.claude-code-2.0.60-win32-x64\resources\native-binary"
Copy-Item "$dir\claude.exe" "$dir\claude.exe.bak"
# Patch
$bytes = [System.IO.File]::ReadAllBytes("$dir\claude.exe")
$enc = [System.Text.Encoding]::GetEncoding("iso-8859-1")
$text = $enc.GetString($bytes)
$idx = 0; $count = 0
while (($idx = $text.IndexOf('"claude-opus-4-5-20251101"', $idx)) -ne -1) {
$r = $enc.GetBytes('"claude-opus-4-6" ')
[Array]::Copy($r, 0, $bytes, $idx, $r.Length)
$count++; $idx += 26
}
[System.IO.File]::WriteAllBytes("$dir\claude.exe", $bytes)
Write-Host "Patched $count occurrence(s)."
Should patch 6 occurrences.
Restart VS Code, ask what model are you? => Opus 4.6.
Adjust path for Cursor (\.cursor\extensions\...). To restore: Copy-Item claude.exe.bak claude.exe -Force (or just copy manually)