Tool calls issues on Windows
Issues the maintainers labelled both platform:windows and area:tools.
980 issues · 148 open · 832 resolved (85%) · first seen May 20, 2025
Is this getting better or worse?
This class of problem is holding steady. 155 new reports in the last 90 days vs 201 in the 90 before — -23%. The open backlog peaked at 193 in 2026-01 and sits at 148 today.
Derived by counting each matching issue from its creation date until it closed. First-party
computation over the anthropics/claude-code tracker — the trend is not published
anywhere upstream.
Which builds report this
451 of these reports name the Claude Code build they were running, spanning 162 releases. Heaviest reporters:
- Claude Code v2.0.76
- Claude Code v2.1.19
- Claude Code v2.1.12
- Claude Code v2.1.119
- Claude Code v2.1.71
- Claude Code v2.1.29
- Claude Code v2.1.23
- Claude Code v2.1.123
Report volume, not a defect count: an issue can mention a build without that build having caused the failure. Versions come from the version string in the bug-report template, matched against real published tags.
Do these get fixed?
Median time to close is 36 days across 832 closures. Of the 832 closures with a recorded reason, 23% were closed as completed and 642 as not-planned or duplicate. The most recent completed fix landed in 2026-10.
Workarounds reported by the community
373 of these issues post a workaround someone says worked. The highest-engagement ones:
- [BUG] file named nul created on windows
- …a regular filename, bypassing Windows reserved name checks. Workaround for users: If you encounter this issue, use Git Bash to remove the file:
Found in the thread of #4928 · resolved - [Feature Request] Claude Desktop: Option to execute commands in WSL instead of Windows
- …ommands, extensions, and file operations happen inside WSL. Workaround (Current) Running Claude Code CLI directly inside WSL terminal works perfectly, but loses the benefits of Claude Desktop's UI and extended context. A…
Found in the description of #12506 · resolved - [Bug] Anthropic API Error: Tool Use Concurrency Limitation
- I tried many workaround without success. In my case, it was a specific PDF file causing the issue. Once unreferenced, it works.
Found in the thread of #9002 · resolved - [BUG] creates `tmpclaude-*-cwd` files in the current working directory
- …ject's working directory regardless of the env var setting. Workaround: Adding to hides them from git status, but doesn't prevent their creation in the project directory.
Found in the thread of #17600 · resolved - [BUG] Claude abuses bash tools for reads, writes, and edits when running in Auto Mode
- …managed settings and roll it out to all the engineers as a work around until this is fixed: You may get an instruction from the harness when running in Auto Mode to favor bash commands over native tools like Read, Edit.…
Found in the thread of #87971 · still open
Excerpts are quoted from the linked issue so you can judge relevance before opening it. Threads that only ask for a workaround, or report that there is none, are excluded. These are community suggestions, not official guidance from Anthropic — read the full thread before applying one.
Matching issues 1–100
Ranked by community engagement (reactions weighted over comments). Listing the top 300 of 980 matches; the statistics above cover all 980.
- [BUG] file named nul created on windows
- [Feature Request] Claude Desktop: Option to execute commands in WSL instead of Windows
- [Bug] Anthropic API Error: Tool Use Concurrency Limitation
- [BUG] creates `tmpclaude-*-cwd` files in the current working directory
- [BUG] Claude abuses bash tools for reads, writes, and edits when running in Auto Mode
- Claude in Chrome extension not connecting despite being installed and enabled
- [Feature Request] Support the standard .agents/skills/ directory for agent skills
- Windows VS Code extension crashes Claude Code with "Error: cannot open _claude_fs_right:<file>. Detail: Unable to resolve filesystem provider with relative file path '_claude_fs_right:<file>'"
- [BUG] Claude Code creates persistent temporary files tmpclaude-* in the workspace
- Windows: Console window flashing when executing tools
- [Bug] Error: No Assistant Message Found
- [BUG] Auto Mode's Bash-first instruction silently disables nested CLAUDE.md and path-scoped rules
- [BUG] Bash tool doesn't capture stdout from shell script files on Windows
- [BUG] VSCode Extension: `.claude/settings.local.json` permissions not respected for Bash/Write/Edit operations (even with `bypassPermissions` mode)
- [Bug] File Edit Fails on Windows with Unexpected Modification Error
- [BUG] Claude Code does not respect file encoding, corrupts Windows-1252 files
- [BUG] `/ralph-wiggum:ralph-loop` has a problem with newline characters.
- Auto mode classifier (claude-opus-4-8) repeatedly unavailable — blocks Bash/Write/Edit
- tmpclaude-*-cwd temporary files are not cleaned up automatically
- Sub-Agents Not Detected: Missing Agents in CLI List Despite Directory Creation
- [BUG] Mousewheel scrolls through input history instead of chat history
- [BUG] Stale .git/index.lock left behind after Bash tool git commands on Windows
- [BUG] CC native on Windows: not really shell aware
- [BUG] LSP workspaceSymbol operation sends empty query parameter
- [BUG] Cowork Edit/Write tools silently truncate files via byte-conservation buffer cap (deterministic, fires at all file sizes)
- Edit tool fails with "File has been unexpectedly modified" even after (Quite critical bug as it cannot code)
- [BUG] Claude Code not finding custom commands in ~/.claude/commands or ./claude/commands
- [BUG]
- [Bug] Claude in Chrome MCP bridge fails on Windows - socket discovery doesn't find named pipes
- [BUG] Web Search Returns 0 Results in WSL
- Bash tool returns empty output when executing shell script files on Windows (MINGW64)
- jdtls-lsp Plugin Fails on Windows Due to Invalid File URI Format
- [BUG] Bash output shows "(No content)" on Windows native since 2.1.x - was working 2 days ago
- typescript-lsp plugin fails on Windows: spawn ENOENT for npm global binaries
- Bug: API Error 400 - tool use concurrency issues
- [BUG] VSCode Extension Doesn't Work Well When on Windows
- [BUG] Frequent "API Error: 400 due to tool use concurrency issues" in VSCode extension
- Windows: pyright-lsp plugin fails with ENOENT - cannot spawn .cmd files
- [BUG] Claude Desktop Drops/Reverts Long Multi-Step Tasks Without Warning
- [Bug] "Unchanged since last read" error when reading file previously accessed in reverted conversation state
- Edit/Write tools fail with 'File has been unexpectedly modified' after Read tool
- [BUG] Autocontinue after 60s not possible to be disabled
- [FEATURE] Expose pasted image data to hooks and plugins
- [BUG] API Error: 400 due to tool use concurrency issues. Run /rewind to recover the conversation.
- Claude in Chrome extension not connecting on Windows despite MCP server showing "connected"
- [BUG] Claude Code will not do anything without manual authorisation every single step
- KRITISCH - ZWEITER KATASTROPHALER DATENVERLUST in 4 Tagen - 1 Monat Arbeit PERMANENT ZERSTÖRT - Zahlender Kunde fordert SOFORTIGE Maßnahmen
- Edit tool returns "File has been unexpectedly modified" when file is NOT modified
- [BUG] WebSearch tool missing input_schema - API Error 422
- Bug Report: Path Patterns in allowedTools Not Honored in Non-Interactive Mode
- [BUG] Claude code leaves temp files
- [BUG] Sub agents can't use tools properly: `Permission to use xxx has been auto-denied in dontAsk mode` even with `--dangerously-skip-permissions`
- [Bug] Claude Code: Persistent Instruction Disregard and Output Quality Degradation
- [BUG] Bash commands sometimes ends with Error: No such file or directory
- Character Encoding Handling Fails for WINDOWS-1252 ADVPL Files
- Presence of ~/.bashrc (even empty) triggers full shell state capture with `set -o onecmd`, breaking npm/subprocess stdout on Windows/Git Bash
- [BUG] Claude Code - LSP Tool Returns Empty Results Despite Server Responding Correctly (Windows)
- [Bug] Windows: terminal/cmd windows flash on every subprocess spawn across multiple CCD sessions
- AskUserQuestion overlay obscures the assistant's previous message
- Edit/Write tools fail with 'File has been unexpectedly modified' on Windows (MINGW)
- Write/Edit tools fail with EEXIST on OneDrive directories (v2.1.69 regression)
- [BUG] Excessive tmpclaude-*-cwd temporary files being created in working directory
- Stray "call"/"court" token before tool calls; internal <invoke> XML printed as text instead of executing (Windows local + cloud Cowork)
- [BUG] MCP servers requiring OAuth authentication don't expose tools - no browser auth flow triggered
- Auto mode discourages Read/Edit/Write in favour of Bash (and TodoWrite is unavailable)
- Windows: Bash tool creates tmpclaude-*-cwd files in working directory
- Auto-update breaks @file_path functionality, displays only subagent options
- clangd LSP plugin: all operations fail with 'trying to get AST for non-added document'
- Claude in Chrome Extension Not Connecting on Windows 11
- Chrome Extension: EADDRINUSE - Native Host and MCP Server both try to create pipe listener
- [BUG] File has been unexpectedly modified
- [Bug] API Error 400 - Tool Use Concurrency Issues - Widespread Regression Affecting All Platforms
- [BUG] Claude Code Edit tool fails on files with CRLF line endings, falsely reporting "File has been unexpectedly modified."
- [BUG] Custom agents no longer work in VSCode extension
- Browser tool can't verify local HTTPS dev servers (self-signed cert + non-rendering pane block all workarounds)
- Agent deleted 2,229 untracked source files without explicit user instruction — catastrophic unrecoverable data loss
- [BUG] (lsp): Malformed file:// URI Generation (v2.1.1+) [RFC-8089]
- "File has been unexpectedly modified" errors break Edit tool in VSCode extension
- [BUG] Edit tool rejects 'File must be read first' even when the file was just written by Bash/Write in the same session
- [BUG] Chrome extension v1.0.40 does not connect to Claude Code CLI --chrome on Windows
- Edit tool replaces Turkish UTF-8 characters with ASCII equivalents
- [BUG] Edit Tool False Positive "File has been unexpectedly modified" on Windows
- [BUG] Screen flickers during task tool work
- [BUG] API Error: 400 `tool_use` ids were found without `tool_result` blocks immediately after: toolu_..... Each `tool_use` block must have a corresponding `tool_result` block in the next message.
- [BUG] ralph-wiggum stop hook triggered in separate session
- [BUG] Plan agent cannot write plan file, state lost (but tokens billed) - UPDATE: both macOS and Windows
- ralph-loop plugin: Windows compatibility issue - stop-hook.sh cannot execute
- [Feature Request] Improve PowerShell shell configuration support for Windows
- File Autocomplete Broken: '@' Trigger Fails on Windows
- Task tools AND TodoWrite both hidden in interactive sessions by live tengu_vellum_ash experiment (newest models); env override ineffective
- Error: File has been unexpectedly modified. Read it again before attempting to write it
- [BUG]
- [BUG] Claude Code CLI hangs forever on Bash()/shell commands in WSL (even with correct user/permissions, native Linux path)
- Claude Code exposes secrets from .env / .dev.vars files via grep -n and Read tool, despite CLAUDE.md prohibitions
- [Feature Request] Tool loader should display loaded tool names instead of generic message
- Custom agents in ~/.claude/agents/ not detected by /agents command
- [BUG] Tool search has broken ranking, causing Claude to fail to find a tool despite exact name match
- [BUG] Silent graceful exit during Write/Bash operations on Windows (NPM installation)
- Hook scripts fail on Windows: backslash paths misinterpreted by Git Bash
- tmpclaude-*-cwd temp files not cleaned up on Windows after bash commands