MCP servers issues on Windows — page 3
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 201–300
Ranked by community engagement (reactions weighted over comments). Listing the top 300 of 756 matches; the statistics above cover all 756.
- 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)
- [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
- [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
- [BUG] MCP OAuth discovery (.well-known) fails with InvalidHTTPResponse across multiple servers
- BSOD (PAGE_FAULT_IN_NONPAGED_AREA / bindflt.sys) triggered by Cowork VM Service starting while a Python-based MCP extension (uv run) scans its own directory under %APPDATA%\Claude
- [Feature Request] MCP tool rendering API to control request panel collapse state
- Windows: `CLAUDE_CODE_SHELL_PREFIX` is used as the executable for stdio MCP server spawns, so a bash-script prefix kills the first connection ("The system cannot find the path specified.")
- [BUG] Desktop app never rebuilds its deferred-tool pool: tools/list_changed and RefreshMcpTools are both no-ops (CLI 2.1.237 works with the identical server — carve-out from #66084)
- [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
- [BUG] Claude Code VS Code extension does not read MCP server config from Claude Desktop MSIX virtualized path
- [BUG] Windows/Cowork: built-in Node.js not used for local MCP plugin servers → spawn node ENOENT (Windows repro of #35175)
- 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