MCP servers issues on Windows — page 3
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. 197 new reports in the last 90 days vs 264 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
222 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 201–300
Ranked by community engagement (reactions weighted over comments). Listing the top 300 of 661 matches; the statistics above cover all 661.
- [BUG] SSE MCP Server fails to connect to Monday.com despite valid endpoint
- [Bug] Compact operation hangs with 9% remaining progress
- UTF-8 Display Issue in MCP Tool Results - Mojibake with German Umlauts
- [BUG] Confusing UX and silent failures for claude mcp add on Windows
- MCP Tools Not Registering Despite Successful Server Connection
- 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
- [BUG] Coursera MCP Connector fails to connect: "Automatic client registration isn't supported" (OAuth Client ID required)
- VSCode extension does not surface claude.ai account connectors (MCP) that the CLI exposes — same version 2.1.156
- VS Code extension's MCP OAuth flow sends malformed resource parameter (double-encoded, params leak into outer URL)
- [BUG] MCP Server Tools Not Callable Despite Authentication
- MCP server registered via 'claude mcp add' not surfacing tools in conversational interface when claude.ai web connectors are also present
- [BUG] MCP servers intermittently fail to connect when invoking skills via claude -p (headless mode)
- Feature Request: Allow Claude Desktop to be configured to only read MCP servers from claude_desktop_config.json (not ~/.claude/.claude.json)
- [BUG] Add connectors not possible and /mcp command doesn't work in fleetview
- [Bug] brand-voice:microsoft-365 MCP server OAuth fails with AADSTS50011 — redirect URI mismatch on every auth attempt
- notifications/claude/channel MCP notifications not injected as <channel> blocks (Telegram plugin)
- stdio MCP server tools dropped when initialize exceeds probe timeout
- [BUG] Cowork Chrome MCP connection failure - persistent "not connected" error
- [FEATURE] Add delete_scheduled_task to the scheduled-tasks MCP (Cowork)
- [BUG] Cowork create_scheduled_task hangs silently 180s on Windows - regression in v1.7196.0
- [Cowork UI] "Unhandled case: [object Object]" banner — MCP tool-result envelope + SDK stream-end-with-error renderer paths
- `claude mcp remove` expands `${VAR}` env-var references inline in `.mcp.json`, leaking secrets
- [BUG] Rider MCP Server fails to detect installed Claude Code, but does detect Codex, which I've never installed or used
- [BUG] Claude Desktop v1.6608 doesn't load local MCP servers from ~/.claude.json in CCD sessions
- XML tool-call converter drops content parameter (size + parallel-batch triggers)
- [mcp] HTTP transport POSTs to URL origin, ignoring configured path component
- [BUG] Cowork — multiple silent failure modes (write tools, Read cache, MCP cache lock) — extends #54847
- [Bug] Windows WebView stuck on chrome-error after preview_stop/preview_start cycle with orphaned processes
- Microsoft365 MCP OAuth fails with AADSTS900971: No reply address provided
- [BUG] MCP per-server timeout not enforced on individual tool calls (stdio hangs indefinitely)
- [BUG] Claude in Chrome v1.0.69: permission_required returned for all MCP navigations to a domain; approval popup never renders
- [Bug] OAuth discovery ignores URL path for subdirectory MCP servers
- [Bug] Auto-mode prevents basic function execution
- [BUG] Gmail MCP `create_draft` lost `threadId` parameter — drafts no longer thread into existing conversations
- HTTP MCP: SDK client does not attach configured --header on tool calls (Claude Code 2.1.114, Windows)
- [BUG] Claude ignores user's MEMORY.md and auto-memory files during debugging — treats external memory as disposable
- [BUG] Gmail MCP: gmail_read_message fails on all draft messages (returns error, no body)
- Subagents inherit all MCP servers, causing Windows stdio saturation in parallel Task waves
- Persistent 502 Bad Gateway from mcp-proxy.anthropic.com — Gmail connector works in claude.ai chat but fails in Claude Code (VS Code extension)
- [BUG] Claude Code does not unpack structured tool output
- Preview tool cuts bottom of viewport in tablet/mobile simulation
- [BUG] Cowork: FUSE Mount Cache Coherency Failure on Host-Side File Writes
- [BUG] Repeated task failure (MCP server integration)
- MCP registry and docs generate broken setup command for Slack (missing clientId/OAuth config)
- [Feature Request] VS Code extension: share MCP servers across conversation tabs instead of spawning per-tab
- Custom subagents cannot access MCP tools despite docs saying they should
- [Bug] MCP tool calls double-dispatched with different tool_use_ids
- [BUG] Claude Code MCP does not use the NO_PROXY setting in environment variables
- [BUG] WRITE TOOL COMPLETEY BROKEN ALL WEEK LONG
- [BUG] MCP tools completely inaccessible from `--agent` main thread — breaks orchestrator pattern
- [BUG] MS365 plugin OAuth authorization fails with two separate errors
- [BUG] MCP server spawning fails for some .bat/.cmd files on Windows
- I cant get Claude CLI to connect to claude chrome.
- Claude in Chrome: Feature gate returns false despite Max Plan account
- Chrome extension fails to connect on Windows 11 - reconnect page closes immediately
- Playwright MCP fails to launch when Chrome is already running on Windows
- Claude in Chrome extension not connecting - screenshots not working
- [BUG] Chrome native host crashes with EADDRINUSE on Windows - named pipe conflict
- [Bug] Chrome Extension (claude-in-chrome) broken on Windows since v2.1.20 - Named Pipe path missing in getSocketPaths
- [Bug] Chrome extension connection not functional despite showing connected status
- MCP tools: Array parameters serialized as strings instead of arrays
- Chrome extension connects to Claude Desktop but not Claude Code on Windows
- [BUG] CHROME extention not working on windows
- Claude in Chrome: SSE server not starting on port 22899 (Windows)
- [BUG] VSCode extension failing to connect on MCP servers.
- [BUG] Tool invocation failure for MCP tools post-compaction patch (Jan 27) — silent backend block on claude.ai
- [Bug] Anthropic API Error 400 during extended thinking with MCP tools
- Windows: claude mcp add mangles /c flag, breaks npx-based MCP servers
- HTTP MCP servers show "connected" but tools are not loaded on Windows
- [BUG] MCP OAuth: state parameter not sent in authorize request but validated on callback
- [BUG] auto-update causes loss of plugin user settings, and update failure leads to plugin load failure
- [BUG] Session Context Quality Degradation + Evasion Behavior - Follow-up to #13229
- Bug: Claude Code times out on USB tethering + VPN (Windows)
- MCP local configuration (.mcp.json) not being read on Windows
- [BUG] Claude’s not reading tool schemas
- Windows Git Bash Path Resolution Failure for MCP Server
- [BUG] Can not connect to MCP servers running by `pnpx` in Windows
- Filesystem MCP access limited to WSL directories - need full computer access
- [BUG] Regression: Claude in Chrome file_upload rejects ALL paths after Claude Desktop update — "can't accept pre-read files" (worked on previous build, before/after captured in one session)
- [BUG] Desktop app ignores bypassPermissions for ccd_session_mgmt tools despite explicit allow list entries; CLI does not prompt
- Desktop: ~3.9k tokens of built-in MCP tool schemas load non-deferred with no opt-out; built-in server instructions exceed the documented 2KB cap
- claude-in-chrome MCP connector absent (Remote env, 24h+)
- Local stdio MCP server fails with "access denied for socket file" when spawned by MSIX-packaged Claude Desktop on Windows (works fine under Codex on the same machine)
- [BUG] Claude in Chrome: navigate + screenshot denied on ALL domains; persists through reinstall, Claude Code restart, and claude.ai allowlist
- Cowork Windows: ALL claude.ai-hosted MCP connectors fail silently since ~May 21, 2026
- [BUG] Claude Code VS Code extension does not read MCP server config from Claude Desktop MSIX virtualized path
- [BUG] Gmail MCP search_threads fails with "Tool execution failed" in Cowork desktop app
- [BUG] Windows: npx-based MCP/plugin servers fail to connect (spawn EINVAL from .cmd shim)
- [BUG] Windows/Cowork: built-in Node.js not used for local MCP plugin servers → spawn node ENOENT (Windows repro of #35175)
- [BUG] MCP stdio server notifications/tools/list_changed does not refresh the tool catalog mid-session
- [BUG]
- [BUG] Claude Desktop and Claude Code CLI never re-register MCP tools after OAuth 2.1 handshake on a remote HTTP server
- [BUG] Auto-update orphans MCP child processes on Windows, breaking next launch of npx-based MCP servers (EBUSY)
- MCP integration broken on Windows: OAuth reconciliation re-flags as "needs auth" after success; stdio MCPs connect but tools never surface
- Claude Desktop re-injects removed MCP connector into every Claude Code session
- [BUG] MCP stdio servers torn down during plugin autoupdate, do not auto-respawn
- [BUG] mcp__ccd_session__spawn_task rejects long multi-line prompts with "prompt undefined" error
- Telegram channel: mcp.notification() returns success but notification never rendered in conversation
- [BUG] the connector-query API the skill uses is returning empty when connectors are present.