Unhandled promise rejection
An async failure escaped every catch and reached the process handler.
59 issues · 1 open · 58 resolved (98%) · first seen Mar 29, 2025
First response · local
What to do now
Most likely: The local Claude Code process crashed while parsing or executing.
- Record the Claude Code version and the first stack frame before restarting.
- Try a fresh session with the same minimal input to distinguish corrupted state from a repeatable crash.
- Preserve logs and compare reports from the same version before downgrading.
These are conservative triage steps, not an official Anthropic fix. Use the issue and workaround evidence below before making a destructive configuration change.
Is this getting better or worse?
This class of problem is converging. 5 new reports in the last 90 days vs 11 in the 90 before — -55%. The open backlog peaked at 9 in 2025-12 and sits at 1 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
20 of these reports name the Claude Code build they were running, spanning 14 releases. Heaviest reporters:
- Claude Code v2.0.76
- Claude Code v2.1.19
- Claude Code v2.1.12
- Claude Code v2.1.1
- Claude Code v2.1.239
- Claude Code v2.1.169
- Claude Code v2.1.116
- Claude Code v2.1.111
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 10 days across 58 closures. Of the 58 closures with a recorded reason, 24% were closed as completed and 44 as not-planned or duplicate. The most recent completed fix landed in 2026-08.
Workarounds reported by the community
15 of these issues post a workaround someone says worked. The highest-engagement ones:
- [BUG] Claude Desktop 1.1.4173 fails to show GUI — @formatjs/intl unhandled promise rejection crashes renderer
- …ult 4. Reboot — same result 5. Directly launch — works fine Workaround Kill all processes, then launch the previous version directly: Claude Model N/A — app doesn't get far enough to connect Is this a regression? Yes, th…
Found in the description of #28271 · resolved - CLI freezes with "No messages returned" error - never recovers
- …with a non-zero status code so the calling script can retry Workaround Attempted I've implemented retry logic in my bash script that: 1. Captures output to a temp file 2. Greps for "No messages returned" 3. Retries up to…
Found in the description of #19060 · resolved - [BUG] Claude Desktop 1.1.4173 crashes on startup on Windows (Squirrel install, sv-SE locale)
- Confirming this also affects MSIX (Microsoft Store) installs, not just Squirrel. Detail Value -------- ------- Version 1.1.4173.0 Install method MSIX (Microsoft Store) OS Windows 1
Found in the thread of #28470 · resolved - Unhandled promise rejection in UI after successful MCP tool chain with Write + Linear update
- …handling around the diff/edit acceptance UI promise chain: Workaround: Break complex tool chains into separate user prompts with 1-2 second delays between operations.
Found in the description of #10072 · resolved - [BUG] `--resume` with empty prompt (`-p ""`) causes unhandled promise rejection and zombie process
- …ate (Input Validation) [reproduce-no-messages-returned.sh]( Workaround Ensure prompts are never empty when using with : Reproduction Script See attached which: 1. Creates a test session 2. Attempts to reproduce the bug 3…
Found in the description of #15918 · resolved
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 1–59
Ranked by community engagement (reactions weighted over comments).
- [BUG] Claude Desktop 1.1.4173 fails to show GUI — @formatjs/intl unhandled promise rejection crashes renderer
- CLI freezes with "No messages returned" error - never recovers
- [Bug] Unhandled Promise Rejection: No assistant message found
- Unhandled Promise Rejection: String Not Found During File Edit Operation
- [BUG] Claude Desktop 1.1.4173 crashes on startup on Windows (Squirrel install, sv-SE locale)
- [BUG] "No messages returned" error crashes CLI in --print mode with unhandled promise rejection
- MCP error -32000: Connection closed - Node.js uncaught exception
- Unhandled Promise Rejection: Shell Communication Failure
- [Bug] Unhandled Promise Rejection in Async Functions 2.1.1
- Unhandled promise rejection in UI after successful MCP tool chain with Write + Linear update
- [BUG] RangeError: Invalid array length
- File Edit Operation Fails with Unhandled Promise Rejection
- [BUG] `--resume` with empty prompt (`-p ""`) causes unhandled promise rejection and zombie process
- [BUG] Session rename fails with ENOENT error: "no such file or directory, open 'n/a'"
- EBADF: bad file descriptor error on lstat for non-existent history.js file (Windows)
- [BUG] Extensions tab permanently breaks after installing a manifest_version 0.4 (uv) extension — getInstalledExtensionsWithState throws "TypeError: u._parse is not a function"
- [BUG] Side panel locks to stale tabId, "No tab with id" cascade (Vivaldi)
- [Regression] Claude Code 2.1.x silently exits with code 1 during HTTP MCP init — loop-protection swallows the underlying exception stacks
- [BUG] Bug report: Claude Desktop crashes on streaming powershell code blocks
- [BUG] Startup keychain credentials error regression on MacOS.
- [Bug] Unhandled promise rejection on non-writable temp directory causes startup hang
- [BUG] File Descriptor Leak in FSWatcher for pending-claude-sessions.json Causes EINVAL Crash
- [BUG] Claude Code CLI hangs with unhandled promise rejection when executing GitHub CLI commands with complex parameter expansion
- [BUG] Unhandled Promise Rejection: 'Bad substitution: re.test' Error in Non-interactive Mode
- [BUG] GPU Corrupted Cache = Black Screen
- [BUG] Claude extension 1.0.68 logs recurring CSP + debugger + runtime errors
- Telegram plugin MCP server crashes: missing error handler on bot.start()
- [BUG] Claude Desktop 1.1.4173 — window fails to open due to unhandled @formatjs/intl error
- Claude Desktop v1.1.4173 crashes on startup: @formatjs/intl unhandled rejection
- [BUG] App Don't work in ARM Microsfot Surface, the window nevers appear
- [BUG] Cannot still on Win11
- [FEATURE] Tool based rule sets.
- [BUG] CLI hangs indefinitely on simple queries (macOS M1, v2.1.37)
- [BUG] Claude crashes with unhandled promise rejection
- [BUG] File watching error on startup: `EINVAL` when watching `.claude` directory
- [BUG] Bad substitution when using heredocs with ${var} — runner not using bash
- [BUG] FSWatcher errors when monitoring system temp sockets (e.g., ssh-askpass-*.sock, vscode-git-*.sock)
- [BUG] Claude Code crashes with unhandled ENOSPC error when disk space is low
- EINVAL error when watching temporary settings file during atomic write
- [BUG] Unhandled promise rejection crash in Ink rendering layer with invalid terminal dimensions
- [Bug] File system watcher fails with unhandled promise rejection in FSWatcher
- [Bug] Unhandled promise rejection in async operation
- [BUG]
- VSCode Extension: Unhandled Promise Rejection When Refactoring in tmux Terminal
- [BUG] Claude Desktop 1.3883.0 — repeated renderer crashes on Windows 11 x64 (BuddyBleTransport `No handler registered`)
- [FEATURE] Add option to disable automatic image processing on paste to support user-controlled image pipelines
- Telegram channel plugin: MCP server crashes on broken stdio pipe (unhandled promise rejection)
- [Bug] Claude Desktop Windows: Renderer process fails to spawn due to @formatjs/intl missing message ID
- [BUG] Claude Desktop v1.1.4173 fails to create BrowserWindow — @formatjs/intl unhandled rejection blocks window init (x64, Windows 11 26200)
- Unhandled Promise rejection when invoking custom slash command
- Unhandled ENXIO error when watching CDP socket pollutes logs
- Unhandled Promise Rejection: MCP Connection Closed Error
- Unhandled Promise Rejection: Duplicate Command Registration in CLI
- [BUG] Desktop (macOS): unhandled GPU-init rejection crashes app when hardware acceleration is disabled
- [BUG][Windows][native-binary] v2.1.159+ silent-exits during startup — v2.1.112 unaffected
- [BUG] SDK: unguarded transport.write() in handleControlRequest catch block causes unhandledRejection
- Telegram channel crashes gateway with unhandled promise rejection on fetch failure
- Unhandled Promise Rejection: Tool closeAllDiffTabs Not Found
- [Bug] stdio MCP server disappears ~53s after reconnect — no exit code, no signal, no exception (related to #40207/#86711)