openclaw - 💡(How to fix) Fix [Bug]: toLowerCase crash on every message in 2026.5.20! bootstrap file name undefined

Bug type

Crash (process/app exits or hangs)

Beta release blocker

No

Summary

After updating to OpenClaw 2026.5.20, every incoming message crashes during bootstrap context building with TypeError: Cannot read properties of undefined (reading 'toLowerCase'), preventing all agent replies.

Steps to reproduce

1. Update to OpenClaw 2026.5.20 (build e510042)
2. Start gateway: openclaw gateway --port 18789
3. Send any Telegram direct message to the bot
4. Observe logs: Embedded agent failed before reply: Cannot read properties of undefined (reading 'toLowerCase')

Expected behavior

Prior versions (e.g., 2026.5.16) processed messages normally without bootstrap context crashes.

Actual behavior

Prior versions (e.g., 2026.5.16) processed messages normally without bootstrap context crashes.

Actual behavior: Gateway starts successfully and Telegram polling connects, but every message fails. Full stack trace:

TypeError: Cannot read properties of undefined (reading 'toLowerCase') at isAgentsBootstrapFile (dist/pi-embedded-helpers-C95s_0hC.js:84:18) at trimBootstrapContent (dist/pi-embedded-helpers-C95s_0hC.js:168:6) at buildBootstrapContextFiles (dist/pi-embedded-helpers-C95s_0hC.js:279:19) at buildBootstrapContextForFiles (dist/bootstrap-files-C7GTd8nX.js:195:9) at resolveBootstrapContextForRun (dist/selection-BmjEdnnA.js:12896:20)

Also hits bootstrap-budget-WP_UMPQC.js:15 (isAgentsBootstrapName).

OpenClaw version

2026.5.20 (e510042)

Operating system

Ubuntu (Linux 7.0.5-orbstack-00330-ge3df4e19b0a0-dirty)

Install method

No response

Model

ollama/kimi-k2.6:cloud

Provider / routing chain

ollama (primary) → openrouter/moonshotai/kimi-k2.6 (fallback)

Additional provider/model setup details

No response

Logs, screenshots, and evidence

Stack trace from gateway log (/tmp/openclaw/openclaw-2026-05-22.log):

  TypeError: Cannot read properties of undefined (reading 'toLowerCase')
      at isAgentsBootstrapFile (pi-embedded-helpers-C95s_0hC.js:84:18)
      at trimBootstrapContent (pi-embedded-helpers-C95s_0hC.js:168:6)
      at buildBootstrapContextFiles (pi-embedded-helpers-C95s_0hC.js:279:19)
      at buildBootstrapContextForFiles (bootstrap-files-C7GTd8nX.js:195:9)
      at resolveBootstrapContextForRun (selection-BmjEdnnA.js:12896:20)
      at runEmbeddedAttempt (selection-BmjEdnnA.js:12876:136)

  Also occurs at:

  TypeError: Cannot read properties of undefined (reading 'toLowerCase')
      at isAgentsBootstrapName (bootstrap-budget-WP_UMPQC.js:15:14)
      at formatBootstrapTruncationWarningLines (bootstrap-budget-WP_UMPQC.js:152:52)

  Preceding log line confirms an undefined filename in the bootstrap list:

  workspace bootstrap file undefined is 129132 chars (limit 10232); truncating in injected context

  Model fallback decision log confirming the crash:

  model fallback decision: decision=candidate_failed requested=ollama/kimi-k2.6:cloud
  candidate=ollama/kimi-k2.6:cloud reason=unknown next=openrouter/moonshotai/kimi-k2.6
  detail=Cannot read properties of undefined (reading 'toLowerCase')

Impact and severity

• Affected users/systems/channels: All users across all channels (Telegram direct messages and groups). The crash happens in the shared bootstrap context builder before any channel-specific code runs.
• Severity: Critical — blocks all agent replies. Gateway starts and connects to channels, but every single message fails before the agent can respond.
• Frequency: Always. 100% of messages reproduce the crash. Observed on 6+ consecutive messages.
• Consequence: Complete agent outage. The gateway is effectively unusable until the crash is patched or the undefined filename entry is removed from the workspace bootstrap list.

Additional information

The crash occurs because a workspace bootstrap file entry has an undefined name property, and two functions call .toLowerCase() without null-safety: isAgentsBootstrapFile(fileName) and isAgentsBootstrapName(name). Temporary workaround is adding ?. optional chaining to both calls in dist/, but the proper fix is upstream: ensuring the bootstrap file list builder never emits entries with undefined names, or adding defensive null checks in the TypeScript source.