Windows activation failure: createRequire invalid file URL breaks command registration in 2.1.51-2.1.53

Claude VS Code Extension Activation Failure on Windows

Report Summary

• Product: Anthropic.claude-code VS Code extension
• Platform: Windows 11 (x64)
• IDE: VS Code 1.109.5 (072586267e68ece9a47aa43f8c108e0dcbf44622)
• Symptom: Claude commands unavailable (command 'claude-vscode.editor.openLast' not found) and Claude panel fails to open reliably
• Root failure observed in logs: extension activation crash due to invalid createRequire() input path

Impact

• Claude extension fails during activation on startup in affected versions.
• Commands contributed by the extension are not registered.
• User cannot use Claude panel/workflows in affected versions.
• Reinstalling affected versions does not resolve the issue.

Timeline (UTC+05:30 local system time)

• February 24, 2026 ~11:43: Failure observed with 2.1.51 activation.
• February 24, 2026 ~12:32: Updated to 2.1.52, same failure pattern.
• February 25, 2026 ~06:23: Updated to 2.1.53, same failure pattern.
• February 25, 2026 ~07:18: Rolled back to 2.1.49; issue resolved and extension operates normally.

Current Working State

• Installed version now: anthropic.claude-code@2.1.49
• Verified command output:
• code --list-extensions --show-versions shows anthropic.claude-code@2.1.49

Reproduction Steps

1. Use Windows 11 + VS Code 1.109.5.
2. Install/upgrade Claude extension to 2.1.51, 2.1.52, or 2.1.53.
3. Restart VS Code and open Claude command (Claude Code: Open / openLast).
4. Observe command missing errors and activation failure in extension host log.

Expected vs Actual

• Expected:
• Extension activates on startup.
• claude-vscode.editor.openLast and related commands are registered and executable.
• Actual:
• Activation throws TypeError before command registration.
• VS Code reports command not found and Claude workflows fail.

Key Evidence (Log Excerpts)

1) Activation failure on 2.1.53

File: C:\Users\yoges\AppData\Roaming\Code\logs\20260225T062110\window2\exthost\exthost.log

396: 2026-02-25 06:23:24.337 [info] ExtensionService#_doActivateExtension Anthropic.claude-code, startup: false, activationEvent: 'onStartupFinished'
397: 2026-02-25 06:23:24.435 [error] Activating extension Anthropic.claude-code failed due to an error:
398: 2026-02-25 06:23:24.436 [error] TypeError: The argument 'filename' must be a file URL object, file URL string, or absolute path string. Received 'file:///home/runner/work/claude-cli-internal/claude-cli-internal/build-agent-sdk/sdk.mjs'
399:     at Module.createRequire (node:internal/modules/cjs/loader:1915:13)
400:     at Object.<anonymous> (c:\Users\yoges\.vscode\extensions\anthropic.claude-code-2.1.53-win32-x64\extension.js:45:4882)

2) Same failure pattern on 2.1.51

File: C:\Users\yoges\AppData\Roaming\Code\logs\20260224T114302\window1\exthost\exthost.log

37: 2026-02-24 11:43:28.871 [info] ExtensionService#_doActivateExtension Anthropic.claude-code, startup: false, activationEvent: 'onStartupFinished'
38: 2026-02-24 11:43:28.954 [error] Activating extension Anthropic.claude-code failed due to an error:
39: 2026-02-24 11:43:28.954 [error] TypeError: The argument 'filename' must be a file URL object, file URL string, or absolute path string. Received 'file:///home/runner/work/claude-cli-internal/claude-cli-internal/build-agent-sdk/sdk.mjs'
41:     at Object.<anonymous> (c:\Users\yoges\.vscode\extensions\anthropic.claude-code-2.1.51-win32-x64\extension.js:45:4602)

3) Version transition evidence (2.1.51 -> 2.1.52)

File: C:\Users\yoges\AppData\Roaming\Code\logs\20260224T114336\sharedprocess.log

1:  2026-02-24 12:14:01.992 [info] Uninstalling extension from the profile: anthropic.claude-code@2.1.51
11: 2026-02-24 12:32:28.824 [info] Extracted extension to ... anthropic.claude-code-2.1.52-win32-x64
12: 2026-02-24 12:32:28.832 [info] Renamed to c:\Users\yoges\.vscode\extensions\anthropic.claude-code-2.1.52-win32-x64
14: 2026-02-24 12:32:28.885 [info] Extension installed successfully: anthropic.claude-code

4) UI symptom (secondary)

File: C:\Users\yoges\AppData\Roaming\Code\logs\20260225T062110\window2\renderer.log

125: 2026-02-25 06:24:58.787 [error] TreeError [DebugRepl] Tree input not set: Error: TreeError [DebugRepl] Tree input not set

The primary blocker is the extension host activation exception shown above.

Why reinstall did not help

• Reinstall/upgrade cycles succeeded at installer level, but runtime activation still fails with the same exception.
• This suggests the issue is in shipped extension runtime logic for affected versions, not local installation corruption.

Workaround that fixed it

• Reverted extension to 2.1.49.
• After rollback, extension activates and Claude workflow is usable again.

Suspected Root Cause

• A runtime path string appears to reference a build-time Linux path:
• file:///home/runner/work/claude-cli-internal/claude-cli-internal/build-agent-sdk/sdk.mjs
• In affected versions, this path is passed into Module.createRequire(...) during activation on Windows, causing immediate failure.

Vendor Request

Please investigate and provide:

1. A fix for Windows activation in versions after 2.1.49.
2. Confirmation whether this is a packaging/build artifact path leak.
3. A patched release or guidance for safe upgrade from 2.1.49.
4. Any additional diagnostics needed; raw logs can be provided on request.

Environment Snapshot

• OS: Windows 11 x64
• VS Code: 1.109.5
• Claude extension affected: 2.1.51, 2.1.52, 2.1.53
• Claude extension working: 2.1.49