--resume crashes with 'UKH is not a function' on session load (2.1.120 regression)

Bug Report — Claude Code 2.1.120 --resume regression

Title: --resume crashes with "UKH is not a function" when selecting a saved session in 2.1.120

---

Summary

In Claude Code 2.1.120, --resume crashes when loading any saved session. The session list renders fine (titles + previews visible), but selecting a session — or passing a UUID directly via claude --resume <uuid> — throws UKH is not a function and exits.

Repro

1. Have any saved session on disk under ~/.claude/projects/<project>/<uuid>.jsonl
2. claude --resume
3. Pick a session from the list (or run claude --resume <uuid> directly)
4. Crash with UKH is not a function

The crash happens during transcript replay, before MCPs initialize — reproducible with no MCP servers configured.

Expected

Session loads and is ready to continue.

Confirmed regression vs 2.1.119

Rolling the symlink back to 2.1.119 and rerunning the same --resume <uuid> against the same .jsonl files loads cleanly. Same shell, same env, same project, same transcripts. Only the binary version differs.

Workaround

• Pin to 2.1.119: ln -sfn ~/.local/share/claude/versions/2.1.119 ~/.local/bin/claude
• Disable autoupdater so it doesn't bump back: "env": { "DISABLE_AUTOUPDATER": "1" } in ~/.claude/settings.json

Environment

• Claude Code: 2.1.120 (broken) / 2.1.119 (works)
• Platform: WSL2, Ubuntu 22.04.5, kernel 5.15.167.4-microsoft-standard-WSL2
• Architecture: x86_64
• Install: standalone (~/.local/share/claude/versions/)

Notes

The error string UKH is not a function is a minified function name, so the failing call site is opaque from the user side — but the fact that it triggers specifically on saved-session load (list renders fine, fresh sessions work fine) points to the resume/replay code path.