MCP servers issues on Windows — page 2
Issues the maintainers labelled both platform:windows and area:mcp.
756 issues · 129 open · 627 resolved (83%) · first seen Jun 19, 2025
Is this getting better or worse?
This class of problem is converging. 182 new reports in the last 90 days vs 243 in the 90 before — -25%. The open backlog peaked at 130 in 2026-09 and sits at 129 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
422 of these reports name the Claude Code build they were running, spanning 171 releases. Heaviest reporters:
- Claude Code v2.1.241
- Claude Code v2.1.119
- Claude Code v2.1.258
- Claude Code v2.1.195
- Claude Code v2.1.114
- Claude Code v2.1.20
- Claude Code v2.1.246
- Claude Code v2.1.232
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 32 days across 627 closures. Of the 627 closures with a recorded reason, 21% were closed as completed and 494 as not-planned or duplicate. The most recent completed fix landed in 2026-10.
Workarounds reported by the community
256 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 - [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 - 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] 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 756 matches; the statistics above cover all 756.
- Feature Request: On-demand/lazy loading for MCP servers
- [BUG] MCP tool streaming output causes scroll jumping/flickering with long conversation context
- [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)
- MCP-originated cross-session sends (`ccd_session_mgmt send_message`) never deliver — payload lost in app layer; receiving session UI hangs on "phantom" turn
- [BUG] [BUG] HTTP MCP connector to Atlassian /v1/mcp/authv2 fails with "Invalid context provided" while /v1/sse works with the same account
- MCP tool-result widgets render as empty boxes (Claude Code Desktop)
- [Bug] CCR routines: 3 structural observability gaps — RemoteTrigger.run HTTP 400 + unmerged claude/* fire artifacts + MCP-permission-prompt deadlocks
- [BUG] M365 connector fails with AADSTS50076 when tenant requires MFA via Conditional Access
- Chrome extension not connecting to Claude Code on Windows
- [Windows] Chrome integration broken - MCP server uses Unix socket paths instead of Named Pipes (regression in v2.1.20+)
- [BUG] Claude Desktop MCP tools stopped working - server connected, no errors, tools not available
- /compact fails with "tools: Tool names must be unique" error when using multiple MCP servers (v2.0.70)
- [BUG] Claude Desktop MCP prompts fail account-wide: "Failed to attach prompt"
- Plan Mode re-prompts on every call for parameterized MCP tools, even when covered by a permissions.allow wildcard
- [BUG] Desktop: MCP widgets have no working export path — "Copy to clipboard" fails with cloud-only advice, "Download file" silently no-ops
- Slack MCP tools silently deactivate mid-session (~1h uptime); claude mcp list still reports Connected
- [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
- [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
- Discord channel plugin: inbound notifications silently dropped on CC 2.1.278 (typing fires, no session turn) — resurfacing #86566
- [FEATURE] Mount MCP Apps widgets collapsed by default (or add a setting)
- [Bug] pdf-viewer plugin: local PDFs always rejected — MCP roots never populated + Windows file:// path mangling (C:\C:\...)
- [BUG] Windows local-agent-mode: agent session processes + MCP fleets not reaped on session end (accumulate across launches)
- [BUG] Cloud MCP connectors (mcp__claude_ai_*) ignore permissions.allow — every call prompts for approval regardless of allowlist entries
- [BUG] Tool restrictions from claude.ai are ignored by the CLI / VS Code extension
- 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
- `.claude.json` stores one project directory under up to three different path spellings, splitting trust, MCP servers, and worktree state across them
- [BUG] elicit MCP
- [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: structuredContent overrides content field, losing actual tool response
- [BUG] MCP server error notifications render as "[object Object]" instead of the error message
- [BUG] MCP server child processes not terminated on Windows after session exit, causing process accumulation
- [BUG]
- [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)]
- Desktop app /mcp OAuth sends a claude:// redirect URI that mcp.cloudflare.com rejects (Redirect URI must use HTTPS or a local loopback address); CLI connection not shared with the desktop session
- [BUG] Windows MSIX 1.32352.1.0: local filesystem MCP server unusable in Cowork sessions - draft-07 outputSchema rejected, and no server version passes both checks
- Desktop: ccd_session_mgmt__send_message reports "Message sent" but never delivers
- [BUG] MCP permission wildcard rules (mcp__<server>__*) stopped matching — regression around v2.1.195, every MCP tool prompts again
- OAuth token exchange fails with AADSTS900144 (missing 'scope') when using --client-id for Entra ID MCP server
- [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: MCP Server Installer UI Fails Silently — All MCP Types Affected
- [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
- 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] 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
- [BUG] Tarea incompleta, bloqueos M365/auto-mode confusos y trato despectivo al usuario
- [BUG] Filesystem MCP server (remote-devices) fails all tool calls: outputSchema declares unsupported draft-07 dialect
- Unreliable untrustworthy Claude Code Wasting time and effort. Dangerous to work with.
- ~10 minute delay before first response in new session (Windows, MSIX) — API call itself is fast
- Locally-configured stdio MCP server connects ("Connected" in claude mcp list) but its tools never surface in the session
- [BUG] Coursera MCP Connector fails to connect: "Automatic client registration isn't supported" (OAuth Client ID required)
- Unparseable MCP tool input is replayed as a {raw,len} wrapper which the model imitates; wrapper is then forwarded to the MCP server without schema validation
- [BUG] Cowork/MCP tool calls fail with -32001 after ~60s even when the server completes and the result arrives