MCP servers issues on Windows — page 2
Issues the maintainers labelled both platform:windows and area:mcp.
661 issues · 123 open · 538 resolved (81%) · first seen Jun 19, 2025
Is this getting better or worse?
This class of problem is converging. 198 new reports in the last 90 days vs 265 in the 90 before — -25%. The open backlog peaked at 123 in 2026-08 and sits at 123 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
360 of these reports name the Claude Code build they were running, spanning 145 releases. Heaviest reporters:
- Claude Code v2.1.195
- Claude Code v2.1.114
- Claude Code v2.1.20
- Claude Code v2.1.237
- Claude Code v2.1.222
- Claude Code v2.1.128
- Claude Code v2.1.211
- Claude Code v2.1.198
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 31 days across 538 closures. Of the 538 closures with a recorded reason, 23% were closed as completed and 414 as not-planned or duplicate. The most recent completed fix landed in 2026-08.
Workarounds reported by the community
221 of these issues post a workaround someone says worked. The highest-engagement ones:
- Claude in Chrome extension not connecting despite being installed and enabled
- ✅ Workaround Confirmed Working (Windows 11, Claude Code 2.1.29) Root cause identified by @kimchi-developer in 21791 — the function (socket path discovery) doesn't return Windows named pipe path. Quick Fix 1. Backup cli.j…
Found in the thread of #21371 · resolved - [CRITICAL] MCP Parameter Serialization Bug in Both Claude Code and Claude Desktop
- …subsequent parameter calls fail with serialization errors. Workaround Currently requires restarting the entire Claude session after each parameter-based MCP operation, making MCP impractical for real workflows. --- Prio…
Found in the description of #4192 · resolved - Critical: No way to bypass MCP tool approval prompts in VSCode extension
- …urpose of MCP servers for external API integration - Forces workarounds (writing custom scripts instead of using MCP) Comparison with CLI Question: Does the CLI version of Claude Code ( terminal command) respect the conf…
Found in the description of #10801 · resolved - [BUG] GitHub connector shows "Connected" but exposes no tools in Cowork (Windows 11, app v1.8555.2.0)
- Same issue here, also in the Claude desktop app (Cowork). GitHub shows "Connected" in Customize → Connectors, but exposes zero GitHub tools in any session — Claude reports no GitHu
Found in the thread of #61682 · still open - [BUG] Cowork Google Drive MCP cannot see content in any Workspace Shared Drive
- Seeing the same. my workaround is to temporarily have a process that copies necessary files to a Drive folder (from the shared drive) and update my Skills to reference this until fixed
Found in the thread of #53442 · 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 101–200
Ranked by community engagement (reactions weighted over comments). Listing the top 300 of 661 matches; the statistics above cover all 661.
- [BUG] Claude Desktop (Windows): MCP tool calls hard-terminated and bridge wedge after repeated timeouts
- [Bug] CCR routines: 3 structural observability gaps — RemoteTrigger.run HTTP 400 + unmerged claude/* fire artifacts + MCP-permission-prompt deadlocks
- Slack MCP tools silently deactivate mid-session (~1h uptime); claude mcp list still reports Connected
- [BUG] Regression after v2.1.112: silent CLI exits on Windows, not fully fixed by NODE_OPTIONS
- [BUG] Cloud MCP (RUBE/Composio) and Remote Control not loading in interactive sessions - Windows
- Bug Report: Telegram Plugin Inbound Messages Broken on Windows
- [BUG] Title: CLAUDE.md project rules overridden by MCP server instructions — runaway token consumption
- getSocketPaths() missing Windows named pipe path — Chrome extension never connects on Windows
- Claude in Chrome: Múltiplas instâncias do native host causam erro EADDRINUSE no Windows
- [Bug] Claude Code performance degradation - behaving erratically
- [Bug] toggling mcp with @mention and then hitting Return does not work
- Infinite loop on all requests - Windows 11 v2.0.1
- [BUG] Claude Code immediately returns "Interrupted by user" on any input
- [BUG] Windows local-agent-mode: agent session processes + MCP fleets not reaped on session end (accumulate across launches)
- [BUG] Tool restrictions from claude.ai are ignored by the CLI / VS Code extension
- [BUG] Telegram channel plugin tools disappear mid-session — Tool not found
- [BUG] Connector tool permissions (Always Allow) reset to default after every Claude Desktop upgrade
- Three intertwined bugs in the Remote/Worktree feature: MCP push, gh ENOENT, plugin-setup hang
- [BUG] Session silently terminates after parallel tool_results on Windows v2.1.107 — no error, no API retry, JSONL just ends
- [BUG] ENABLE_TOOL_SEARCH not working in Desktop App - MCP tools fully loaded despite settings
- [BUG] telegram bot not replying.
- [BUG] MCP client silently drops all tools when third-party server includes outputSchema in tools/list response
- [BUG] Claude in Chrome extension not connecting - MCP shows connected but extension unresponsive
- Chrome native host crashes on Windows - Bun 1.3.5 panic on named pipe creation
- [Bug] MCP_TOOL_TIMEOUT not respected for long-running HTTP tool calls
- [BUG] Issue with Atlassian MCP
- [BUG] MCP servers never initialize on Windows/PowerShell - silent failure
- [BUG] Stuck in Tool use, no response for any operation
- [BUG] Prompt cache lookup fails intermittently mid-session — cache_read pinned to the stable-prefix boundary, 89 full-context rewrites across 9 days (~59M excess cache_creation tokens)
- [Bug] pdf-viewer plugin: local PDFs always rejected — MCP roots never populated + Windows file:// path mangling (C:\C:\...)
- [BUG] Cloud MCP connectors (mcp__claude_ai_*) ignore permissions.allow — every call prompts for approval regardless of allowlist entries
- [BUG] Vercel MCP OAuth token not persisted — empty accessToken after every auth
- [BUG] Claude in Chrome (VS Code 2.1.160): `mcp_set_servers` publishes only SDK tools to the model and gates even that on `sdkServersChanged` — so a dynamically-added stdio server connects (status/pill shows its tools) but the model never receives them
- [BUG] MCP server child processes not terminated on Windows after session exit, causing process accumulation
- [BUG] Scheduled Claude Routine stalls on deferred tool schema loading — requires manual input to continue
- enableAllProjectMcpServers should default to false for security
- [Windows] Telegram channel inbound notifications not received by Claude Code
- Telegram channel MCP server dies shortly after startup on Windows
- [BUG] Local stdio MCP servers not loaded on native Windows
- MCP MySQL tool parser rejects cross-schema dot notation (schema.table)
- Chrome extension: Bun panics on Windows when creating named pipe for native host
- Windows: Chrome extension never connects - cc4() returns file paths instead of named pipe path
- [BUG] Chrome extension native messaging connection not initiated on Windows when Claude Desktop is closed
- [BUG] BUG REPORT: Claude Desktop Projects - Filesystem MCP Freeze
- [BUG] Adding a local MCP server with additional arguments does not work in PowerShell (on Windows)
- [BUG] Custom MCP servers silently fail after "Extension not found" check
- [BUG] Figma app local MCP Server connection failure (Windows native)
- [MCP servers “Failed to connect” on Windows 11 (Node 22, npm 11.5.1, Claude CLI 1.0.62)]
- [BUG] elicit MCP
- OAuth token exchange fails with AADSTS900144 (missing 'scope') when using --client-id for Entra ID MCP server
- [BUG] MCP: structuredContent overrides content field, losing actual tool response
- Bug: MCP Server Installer UI Fails Silently — All MCP Types Affected
- [BUG] MCP server error notifications render as "[object Object]" instead of the error message
- scheduled-tasks dispatcher stopped honoring SKILL.md `model:` frontmatter on/around 2026-04-27 ~01-02 UTC
- Stdio MCP server cwd field silently ignored on Windows (2.1.123)
- [BUG]
- [BUG] MCP tools from commented-out server entries still appear in context
- MCP servers using npx fail to connect in VS Code 1.112
- [BUG] degraded tool usage when on-demand
- [BUG] MCP servers, plugins, and credentials not persisting between sessions (Windows)
- [BUG] Chrome native messaging host crashes with Bun panic when Windows username contains Unicode emoji
- Claude in Chrome extension not connecting despite MCP server showing connected
- [Bug] Claude exits silently during debugging with background commands
- [Feature Request] Add tool filtering for MCPs to reduce context window usage
- [BUG] v2.0.68 does not display MCP interaction in subagent even with --debug and/or --verbose
- [FEATURE] Cross-platform .mcp.json project files
- CP warning for Windows npx commands should be suppressed when server connects successfully
- [BUG] Opus 4.1 model is not using MCP servers
- [BUG] Unable to connect to stdio MCP proxies from Windows Terminal
- Desktop: ccd_session_mgmt__send_message reports "Message sent" but never delivers
- Locally-configured stdio MCP server connects ("Connected" in claude mcp list) but its tools never surface in the session
- [BUG] Cowork/MCP tool calls fail with -32001 after ~60s even when the server completes and the result arrives
- [BUG] MCP permission wildcard rules (mcp__<server>__*) stopped matching — regression around v2.1.195, every MCP tool prompts again
- [BUG] MSIX + Smart App Control: Windows-MCP blocked (os error 4551), and Directory extension install silently fails ("installDxtFromDirectory: reply was never sent") on 1.12603.1
- [BUG] MCP stdio: tool result written by server in <100ms is never processed — 3-min stall, then "[Tool result missing due to internal error]" (Windows, 2.1.162)
- [BUG] Claude Desktop - Code - MCP InputSchema with nullable arrays has type silently dropped
- MCP SSE transport ignores relative endpoint URLs; Streamable HTTP (type: http) silently not loaded
- [BUG] MCP tools/call returns "Tool call failed: 500" against server that responds with HTTP 200
- [BUG] Linear MCP tools appear as "deferred" and fail to work reliably across sessions despite server showing Connected
- [BUG] Inconsistencies between Claude Code CLI and Claude Code in Desktop app: MCPs, Skills, async usage, and opusplan mode
- Process crashes with exit code 3221225477 (0xC0000005 STATUS_ACCESS_VIOLATION) on Windows ARM
- Claude ignores installed MCP skills, writes wrong code 3x instead of verifying first (Shopify)
- [BUG] [BUG] Supabase MCP OAuth token not persisting between sessions on Windows - Claude Code Desktop
- Claude Code (VSC Extension) - MCP handshake timeout
- Claude in Chrome extension stops connecting spontaneously — MCP shows connected but extension reports not connected
- [BUG] Project .mcp.json not loaded when using Perforce
- Windows: claude mcp add breaks /c flag, Playwright MCP plugin fails — working workaround
- Channel plugin MCP server silently fails to start on restart
- Telegram plugin: inbound MCP notifications not reaching conversation (outbound works)
- [BUG] notifications/claude/channel MCP notifications silently dropped — channel plugins (Telegram, fakechat) non-functional
- [BUG] doctor shows schema error in .mcp.json but MCP server are loaded: mcpServers: Does not adhere to MCP server configuration schema
- [BUG] Claude in Chrome MCP returns stale/cached tab data across sessions
- [BUG] Claude Code kills ALL Python processes system-wide at turn boundaries (Windows)
- [BUG] 2.1.61 wiped out .claude.json - all settings/MCPs gone
- Claude in Chrome MCP - Browser extension not connected despite native host running
- Bug Report: Chrome Extension MCP Connection Failing
- Chrome native messaging host crashes on startup (Bun panic)
- [BUG] Claude Code VSC Plugin Hangs Intermittently
- [BUG] Claude code does not support MCP protocol version 2025-06-18 needed by Lens Studio and others
- [BUG] MCP Tools Not Accessible via MCPSearch Despite Server Connection Description