The complete library

All Windows AI tool fixes

Each page targets one searchable error signature and tells you whether the workaround was confirmed, partial, or still unknown.

Fix “AbsolutePathBuf deserialized without a base path” in Codex on Windows

Invalid request: AbsolutePathBuf deserialized without a base path

Two Windows reports point to workspace-mode and path-state failures. Switching out of WSL mode or reloading the VS Code window restored chat creation temporarily.

4 min

Codex fatal error: “HW capability found … but requested …” on Windows

Fatal Error: HW capability found: 0x178BFBFF 0x7EF8320B, but HW capability requested: 0x200000 0x00

A Windows regression affected some Ryzen systems. Version 0.104 or WSL were the repeatedly reported escape hatches while newer native builds failed before startup.

5 min

Fix “Windows cannot find codex-windows-sandbox-setup.exe”

Windows cannot find 'codex-windows-sandbox-setup.exe'

Standalone and extension installs can lose the sandbox helper path. Running Codex from the official release package’s bin folder completed setup in a clean Windows VM.

5 min

Fix Codex config.toml “missing escaped value” on Windows

missing escaped value, expected b, e, f, n, r, \, quote, x, u, U

A double-quoted Windows path makes TOML interpret backslashes as escapes. Forward slashes or literal single-quoted TOML strings fixed the reported startup failure.

4 min

Codex WSL error: codex-linux-sandbox “doesn’t exist” (ENOENT)

Unable to spawn codex-linux-sandbox because it doesn't exist on the filesystem (ENOENT)

A full Codex Desktop restart rebuilt the missing helper directory for one reporter. Native Windows mode or the Ubuntu CLI are safer fallbacks by repository location.

4 min

Fix “Unable to locate the Codex CLI binary” on Windows

Unable to locate the Codex CLI binary. Set CODEX_CLI_PATH or ensure the Electron resources include bin/codex.

A move or reinstall to the C: drive restored Codex Desktop for the original reporter. Check the resolved install before creating a custom wrapper.

4 min

Fix Claude Code MCP “spawn npx ENOENT” on Windows

SPAWN ERROR: ENOENT spawn npx ENOENT

On native Windows, route NPX through cmd.exe. A reporter confirmed the change connected six official plugin MCPs, including Context7 and Playwright.

5 min

Claude Desktop MCP “UtilityProcess spawn timeout” on Windows

MCP X: UtilityProcess spawn timeout — Could not connect to MCP server X

One Windows 11 report found three or more stdio servers unreliable while two remained stable. There is no confirmed permanent fix in the cited reports.

4 min

Fix Playwright MCP reconnect failure and /c → C:/ rewrite on Windows

Failed to reconnect to plugin:playwright:playwright

A native Windows report found Claude serialized cmd.exe’s /c as C:/. Launching the Playwright MCP CLI directly with Node bypassed the broken command transformation.

5 min

Claude Desktop shows “No servers added” with a valid MCP config

No servers added

The Microsoft Store/MSIX build could silently ignore the usual AppData config path. The original reporter restored MCP loading with Anthropic’s direct-download desktop build.

5 min

MCP filesystem rejects a valid Windows subfolder as “outside allowed directories”

Access denied - path outside allowed directories: c:\... not in C:\...

Windows drive-letter casing can break a textual containment check. Matching both paths to an uppercase drive letter is a partial workaround, not a universal fix.

4 min