[BUG] Claude Desktop 1.2773.0 OOM crash on startup — skills sync memory leak

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

CLAUDE DESKTOP BUG REPORT — V8 OOM crash on startup (1.2773.0)

Submitted by: Ryan Bredemeyer (ryanbredemeyer@gmail.com)
Plan: Max ($200/month)
Date: April 15, 2026

SUMMARY:
Claude Desktop 1.2773.0 crashes with V8 "JavaScript heap out of memory"
approximately 18 seconds after launch, every single time. App is completely
unusable. Started after the most recent update (around April 14, 2026).
Previous version 1.1617.0 works but lacks the Claude Code / Cowork top bar UI.

SYSTEM:

• macOS 14.3 (Sonoma), build 23D56
• Mac with Intel Core i9-10910 @ 3.60GHz, 128 GB RAM
• Electron 41.2.0, Node 24.14.0, Chrome 146.0.7680.179
• Claude Desktop version: 1.2773.0

REPRODUCTION:

1. Launch Claude Desktop 1.2773.0 normally
2. App window appears briefly
3. ~18 seconds later, app crashes

100% reproducible. Tested 6+ times with:

• Fresh caches (deleted all Cache, Code Cache, GPUCache, vm_bundles)
• Fresh web state (deleted Local Storage, Session Storage, IndexedDB)
• Disabled coworkScheduledTasksEnabled + ccdScheduledTasksEnabled in config
• Removed skills-plugin cache
• None of these helped. Crash is in the app binary itself.

ROOT CAUSE (from stderr capture):
The V8 heap grows to ~3.6 GB in 18 seconds and hits the ceiling:

[pid:0415/193846:ERROR:electron/shell/common/node_bindings.cc:185]
OOM error in V8: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory

Last GCs before crash:
Mark-Compact (reduce) 3553.5 (3593.5) -> 3553.4 (3559.2) MB,
pooled: 0.0 MB, 39.82 / 0.00 ms (average mu = 0.336, current mu = 0.020)
last resort; GC in old space requested

This is NOT a system RAM issue (128 GB available, 92 GB free at crash time).
This is a runaway allocation in the main Node process.

KEY FINDING:
Launching with --disable-background-networking flag PREVENTS the crash.
App stays alive indefinitely but the top bar (Claude Code / Cowork) doesn't
render. Sentry breadcrumb comparison:

CRASH run: 7x "skills/download-dot-skill-file" HTTP calls before OOM
ALIVE run (--disable-background-networking): 0x skill download calls

The skills sync loop appears to be the source of the memory leak.

WORKAROUND:
Rolled back to version 1.1617.0 from Time Machine. Works but lacks
Claude Code desktop UI and Cowork top bar (features that shipped with
the 1.2xxx version line).

IMPACT:

• Cannot use Claude Code in desktop app
• Cannot use Cowork features
• Cannot access Claude Code conversation history through the UI
• All local skills, MCP config, and session data intact on disk but

inaccessible through the broken version

• Paying $200/month for Max plan, app completely unusable since April 14

REQUESTED:

• Hotfix for 1.2773.0 skills sync memory leak
• Or: provide a downloadable link to last known good version with

Claude Code UI (between 1.1617.0 and 1.2773.0, if one exists)

All diagnostic data (crash dumps, stderr logs, sentry breadcrumbs)
available on request.

What Should Happen?

Claude Desktop should launch and remain stable. The Chat, Code, and Cowork tabs should all be
functional.

Error Messages/Logs

[8434:0x12c002d4000] 18432 ms: Mark-Compact (reduce) 3553.5 (3593.5) -> 3553.4 (3559.2) MB,     
  pooled: 0.0 MB, 39.82 / 0.00 ms (average mu = 0.336, current mu = 0.020) last resort; GC in old
  space requested                                                                                 
  [8434:0x12c002d4000] 18471 ms: Mark-Compact (reduce) 3553.4 (3559.2) -> 3553.4 (3558.2) MB,
  pooled: 0.0 MB, 39.32 / 0.00 ms (average mu = 0.201, current mu = 0.000) last resort; GC in old 
  space requested                 
  [8434:0415/193846.787361:ERROR:electron/shell/common/node_bindings.cc:185] OOM error in V8:     
  CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory                           
                                                                       
  Sentry breadcrumbs show 7x skills/download-dot-skill-file HTTP calls before OOM.                
  Launching with --disable-background-networking prevents crash (0 skill download calls) but      
  disables Code/Cowork UI.                                                                  
  Clicking the Code tab with --disable-background-networking triggers the same OOM after ~15      
  seconds.

Steps to Reproduce

1. Install Claude Desktop 1.2773.0 on macOS 14.3 (Sonoma)
2. Launch normally — app crashes with V8 OOM after ~18 seconds, every time
3. Launch with --disable-background-networking — app stays alive, Chat works, but Code/Cowork

tabs crash on click

1. Confirmed via Sentry breadcrumbs: crash correlates with skills/download-dot-skill-file sync

loop (7 calls before OOM vs 0 calls when flag is set)

1. Tested with: fresh caches, fresh web state, disabled scheduled tasks, removed skills cache —

none helped. Bug is in the app binary.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

1.1617.0

Claude Code Version

1.2773.0 (Claude Desktop, not CLI)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

System: iMac20,2, Intel i9-10910 @ 3.60GHz, 128GB RAM, 92GB free at crash time.
Electron 41.2.0, Node 24.14.0, Chrome 146.0.7680.179.

This is NOT a system RAM issue — 92GB free. The V8 per-process heap hits ~3.6GB in 18 seconds
from a runaway allocation in the skills sync loop.

Root cause: The _syncSkills() method in the main process calls skills/download-dot-skill-file
for each enabled skill. The download handler (FRe → lqt function) leaks ~500MB per call. 7
skills × ~500MB = 3.5GB → OOM.

Proof: Extracted app.asar, found the sync code in .vite/build/index.js. The downloadSkills()
method uses a concurrency queue (YQ) to download skill files via FRe(). Adding a return before
LRe() (the remote fetch) would fix it, but modifying app.asar breaks the code signature.

Workaround: Rolled back to 1.1617.0 via Time Machine. Functional for Chat only — no Code/Cowork
UI (feature didn't exist in that version).

Contact: ryanbredemeyer@gmail.com — Max plan customer, app completely unusable since April 14.