[BUG] VS Code Claude Code Extension Stopped Working. (TypeError: The argument 'filename' must be a file URL object, file URL string, or absolute path string...)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Overview

The Claude Code for VS Code extension has suddenly stopped working.

When I open the extension's panel, It fails to initialize while a progress bar spins indefinitely. See this screenshot:

<img width="2109" height="1452" alt="Image" src="https://github.com/user-attachments/assets/ea87d013-fe84-422b-a168-5a2669614635" />

Output Console Errors

To begin debugging, I switched to the Output Console, and selected "Extension Host" and found several errors related to the Claude Code extension failing to activate.

2026-02-24 20:38:14.978 [error] Activating extension Anthropic.claude-code failed due to an error:
2026-02-24 20:38:14.978 [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'
at Module.createRequire (node:internal/modules/cjs/loader:1915:13)
at Object.<anonymous> (c:\Users\futur\.vscode\extensions\anthropic.claude-code-2.1.53-win32-x64\extension.js:45:4882)
at Module._compile (node:internal/modules/cjs/loader:1714:14)
at Module._extensions..js (node:internal/modules/cjs/loader:1848:10)
at Module.load (node:internal/modules/cjs/loader:1448:32)
at Module._load (node:internal/modules/cjs/loader:1270:12)
at c._load (node:electron/js2c/node_init:2:17993)
at e._load (file:///c:/Users/futur/AppData/Local/Programs/Microsoft%20VS%20Code/072586267e/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:405:6055)
at t._load (file:///c:/Users/futur/AppData/Local/Programs/Microsoft%20VS%20Code/072586267e/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:223:22773)
at s._load (file:///c:/Users/futur/AppData/Local/Programs/Microsoft%20VS%20Code/072586267e/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:215:24706)
at TracingChannel.traceSync (node:diagnostics_channel:328:14)
at wrapModuleLoad (node:internal/modules/cjs/loader:244:24)
at Module.require (node:internal/modules/cjs/loader:1470:12)
at require (node:internal/modules/helpers:147:16)
at pee.Cb (file:///c:/Users/futur/AppData/Local/Programs/Microsoft%20VS%20Code/072586267e/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:254:1256)

---

I've tried all of the following steps:

1. Uninstalling the extension completely
2. Deleting its folder in C:\Users\username\.vscode\extensions\anthropic.claude-code-2.1.53-win32-x64, and then re-installing.
3. Clearing this directory: C:\Users\username\.claude\cache
4. Deleting the contents of C:\Users\username\AppData\Roaming\Code\User\workspaceStorage
5. Moving the contents of C:\Users\username\AppData\Roaming\Code\User\globalStorage to C:\Users\username\AppData\Roaming\Code\User\globalStorage-old

It was working completely fine a couple hours ago, and after I completed a C# project and migrated it to a new folder, the extension stopped working on the next launch of VS Code.

I use this IDE Extension extensively to get mission critical work done. It's my daily driver and really have no other alternative.

What Should Happen?

The Claude Code pane should load / initialize.

Error Messages/Logs

Error from the Output Console in VS Code:


2026-02-24 20:38:14.978 [error] Activating extension Anthropic.claude-code failed due to an error:
2026-02-24 20:38:14.978 [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'
at Module.createRequire (node:internal/modules/cjs/loader:1915:13)
at Object.<anonymous> (c:\Users\futur\.vscode\extensions\anthropic.claude-code-2.1.53-win32-x64\extension.js:45:4882)
at Module._compile (node:internal/modules/cjs/loader:1714:14)
at Module._extensions..js (node:internal/modules/cjs/loader:1848:10)
at Module.load (node:internal/modules/cjs/loader:1448:32)
at Module._load (node:internal/modules/cjs/loader:1270:12)
at c._load (node:electron/js2c/node_init:2:17993)
at e._load (file:///c:/Users/futur/AppData/Local/Programs/Microsoft%20VS%20Code/072586267e/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:405:6055)
at t._load (file:///c:/Users/futur/AppData/Local/Programs/Microsoft%20VS%20Code/072586267e/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:223:22773)
at s._load (file:///c:/Users/futur/AppData/Local/Programs/Microsoft%20VS%20Code/072586267e/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:215:24706)
at TracingChannel.traceSync (node:diagnostics_channel:328:14)
at wrapModuleLoad (node:internal/modules/cjs/loader:244:24)
at Module.require (node:internal/modules/cjs/loader:1470:12)
at require (node:internal/modules/helpers:147:16)
at pee.Cb (file:///c:/Users/futur/AppData/Local/Programs/Microsoft%20VS%20Code/072586267e/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:254:1256)

Steps to Reproduce

I don't know exactly how to reproduce this. For me it's as simple as:

1. Opening VS Code
2. Opening the Claude Code Panel
3. Watching as it never loads

---

Extension Version:

Version 2.1.53
Released on 6/18/2025, 11:32:16 AM
Last updated
2/24/2026, 6:22:34 PM

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Not sure. Whatever the version was before this latest version.

Claude Code Version

2.1.53 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Some log files:

C:\Users\username\AppData\Roaming\Claude\logs\unknown-window.log (Only included entries from today)

unknown-window.log

C:\Users\username\AppData\Roaming\Claude\logs\main.log (Only included entries from today)

main.log