### Preflight Checklist - [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) 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 with Cowork has become unusable since approximately Februa

[BUG] Claude Desktop Cowork: Freezing, API 500 errors, and 12GB VM bundle causing instability on macOS 26.3

Resolved 💬 3 comments Opened Feb 18, 2026 by jackie3169 Closed Feb 22, 2026

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?

<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Claude Desktop with Cowork has become unusable since approximately February 16, 2026. The app freezes repeatedly, Cowork sessions fail with API 500 errors before the workspace finishes setting up, and the VM bundle immediately balloons to 12GB after a clean install. This persists through full reinstallation, reboot, and clearing all cached data.</p>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Environment</h2>
<ul class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2"><strong>Claude Desktop Version:</strong> 1.1.3363</li>
<li class="whitespace-normal break-words pl-2"><strong>Platform:</strong> macOS 26.3 (Build 25D125)</li>
<li class="whitespace-normal break-words pl-2"><strong>Hardware:</strong> Apple Silicon Mac, 16GB RAM, 460GB SSD (80GB free)</li>
<li class="whitespace-normal break-words pl-2"><strong>Subscription:</strong> Pro</li>
<li class="whitespace-normal break-words pl-2"><strong>Network:</strong> Standard Wi-Fi, no VPN, no antivirus</li>
</ul>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Steps to Reproduce</h2>
<ol class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2">Clean install Claude Desktop (or reinstall after removing previous version)</li>
<li class="whitespace-normal break-words pl-2">Open Claude Desktop</li>
<li class="whitespace-normal break-words pl-2">Switch to Cowork tab</li>
<li class="whitespace-normal break-words pl-2">Workspace setup begins ("Setting up Claude's workspace...")</li>
<li class="whitespace-normal break-words pl-2">Submit a task before or shortly after workspace setup completes</li>
<li class="whitespace-normal break-words pl-2">Observe API 500 error and "This task didn't load properly" message</li>
<li class="whitespace-normal break-words pl-2">App becomes unresponsive/freezes, requiring force quit</li>
<li class="whitespace-normal break-words pl-2">On relaunch, various error messages appear</li>
</ol>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Expected Behavior</h2>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Cowork workspace should set up fully, accept tasks, and run without freezing or API errors.</p>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Actual Behavior</h2>
<h3 class="text-text-100 mt-2 -mb-1 text-base font-bold">Issue 1: API 500 Internal Server Error</h3>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Cowork returns the following error, sometimes while the workspace is still setting up (observed at 85% setup):</p>
<div class="relative group/copy bg-bg-000/50 border-0.5 border-border-400 rounded-lg"><div class="sticky opacity-0 group-hover/copy:opacity-100 top-2 py-2 h-12 w-0 float-right"><div class="absolute right-0 h-8 px-2 items-center inline-flex z-10"><button class="inline-flex
items-center
justify-center
relative
shrink-0
can-focus
select-none
disabled:pointer-events-none
disabled:opacity-50
disabled:shadow-none
disabled:drop-shadow-none border-transparent
transition
font-base
duration-300
ease-[cubic-bezier(0.165,0.85,0.45,1)] h-8 w-8 rounded-md active:scale-95 backdrop-blur-md Button_ghost__BUAoh" type="button" aria-label="Copy to clipboard" data-state="closed"><div class="relative"><div class="transition-all opacity-100 scale-100" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-100 scale-100" aria-hidden="true" style="flex-shrink: 0;"><path d="M12.5 3C13.3284 3 14 3.67157 14 4.5V6H15.5C16.3284 6 17 6.67157 17 7.5V15.5C17 16.3284 16.3284 17 15.5 17H7.5C6.67157 17 6 16.3284 6 15.5V14H4.5C3.67157 14 3 13.3284 3 12.5V4.5C3 3.67157 3.67157 3 4.5 3H12.5ZM14 12.5C14 13.3284 13.3284 14 12.5 14H7V15.5C7 15.7761 7.22386 16 7.5 16H15.5C15.7761 16 16 15.7761 16 15.5V7.5C16 7.22386 15.7761 7 15.5 7H14V12.5ZM4.5 4C4.22386 4 4 4.22386 4 4.5V12.5C4 12.7761 4.22386 13 4.5 13H12.5C12.7761 13 13 12.7761 13 12.5V4.5C13 4.22386 12.7761 4 12.5 4H4.5Z"></path></svg></div><div class="absolute inset-0 flex items-center justify-center"><div class="transition-all opacity-0 scale-50" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-0 scale-50" aria-hidden="true" style="flex-shrink: 0;"><path d="M15.1883 5.10908C15.3699 4.96398 15.6346 4.96153 15.8202 5.11592C16.0056 5.27067 16.0504 5.53125 15.9403 5.73605L15.8836 5.82003L8.38354 14.8202C8.29361 14.9279 8.16242 14.9925 8.02221 14.9989C7.88203 15.0051 7.74545 14.9526 7.64622 14.8534L4.14617 11.3533L4.08172 11.2752C3.95384 11.0811 3.97542 10.817 4.14617 10.6463C4.31693 10.4755 4.58105 10.4539 4.77509 10.5818L4.85321 10.6463L7.96556 13.7586L15.1161 5.1794L15.1883 5.10908Z"></path></svg></div></div></div></button></div></div><div class="overflow-x-auto"><pre class="code-block__code !my-0 !rounded-lg !text-sm !leading-relaxed p-3.5" style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono);"><code style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono); white-space: pre-wrap;"><span><span>API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CYFn7QMyPcrNmWWz9K8GR"}</span></span></code></pre></div></div>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Followed by:</p>
<div class="relative group/copy bg-bg-000/50 border-0.5 border-border-400 rounded-lg"><div class="sticky opacity-0 group-hover/copy:opacity-100 top-2 py-2 h-12 w-0 float-right"><div class="absolute right-0 h-8 px-2 items-center inline-flex z-10"><button class="inline-flex
items-center
justify-center
relative
shrink-0
can-focus
select-none
disabled:pointer-events-none
disabled:opacity-50
disabled:shadow-none
disabled:drop-shadow-none border-transparent
transition
font-base
duration-300
ease-[cubic-bezier(0.165,0.85,0.45,1)] h-8 w-8 rounded-md active:scale-95 backdrop-blur-md Button_ghost__BUAoh" type="button" aria-label="Copy to clipboard" data-state="closed"><div class="relative"><div class="transition-all opacity-100 scale-100" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-100 scale-100" aria-hidden="true" style="flex-shrink: 0;"><path d="M12.5 3C13.3284 3 14 3.67157 14 4.5V6H15.5C16.3284 6 17 6.67157 17 7.5V15.5C17 16.3284 16.3284 17 15.5 17H7.5C6.67157 17 6 16.3284 6 15.5V14H4.5C3.67157 14 3 13.3284 3 12.5V4.5C3 3.67157 3.67157 3 4.5 3H12.5ZM14 12.5C14 13.3284 13.3284 14 12.5 14H7V15.5C7 15.7761 7.22386 16 7.5 16H15.5C15.7761 16 16 15.7761 16 15.5V7.5C16 7.22386 15.7761 7 15.5 7H14V12.5ZM4.5 4C4.22386 4 4 4.22386 4 4.5V12.5C4 12.7761 4.22386 13 4.5 13H12.5C12.7761 13 13 12.7761 13 12.5V4.5C13 4.22386 12.7761 4 12.5 4H4.5Z"></path></svg></div><div class="absolute inset-0 flex items-center justify-center"><div class="transition-all opacity-0 scale-50" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-0 scale-50" aria-hidden="true" style="flex-shrink: 0;"><path d="M15.1883 5.10908C15.3699 4.96398 15.6346 4.96153 15.8202 5.11592C16.0056 5.27067 16.0504 5.53125 15.9403 5.73605L15.8836 5.82003L8.38354 14.8202C8.29361 14.9279 8.16242 14.9925 8.02221 14.9989C7.88203 15.0051 7.74545 14.9526 7.64622 14.8534L4.14617 11.3533L4.08172 11.2752C3.95384 11.0811 3.97542 10.817 4.14617 10.6463C4.31693 10.4755 4.58105 10.4539 4.77509 10.5818L4.85321 10.6463L7.96556 13.7586L15.1161 5.1794L15.1883 5.10908Z"></path></svg></div></div></div></button></div></div><div class="overflow-x-auto"><pre class="code-block__code !my-0 !rounded-lg !text-sm !leading-relaxed p-3.5" style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono);"><code style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono); white-space: pre-wrap;"><span><span>⚠ This task didn't load properly
</span></span><span>API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CYFn7QMyPcrNmWWz9K8GR"}</span></code></pre></div></div>
<h3 class="text-text-100 mt-2 -mb-1 text-base font-bold">Issue 2: 12GB VM Bundle on Clean Install</h3>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Immediately after a fresh install and first Cowork launch, the VM bundle grows to 12GB:</p>
<div class="relative group/copy bg-bg-000/50 border-0.5 border-border-400 rounded-lg"><div class="sticky opacity-0 group-hover/copy:opacity-100 top-2 py-2 h-12 w-0 float-right"><div class="absolute right-0 h-8 px-2 items-center inline-flex z-10"><button class="inline-flex
items-center
justify-center
relative
shrink-0
can-focus
select-none
disabled:pointer-events-none
disabled:opacity-50
disabled:shadow-none
disabled:drop-shadow-none border-transparent
transition
font-base
duration-300
ease-[cubic-bezier(0.165,0.85,0.45,1)] h-8 w-8 rounded-md active:scale-95 backdrop-blur-md Button_ghost__BUAoh" type="button" aria-label="Copy to clipboard" data-state="closed"><div class="relative"><div class="transition-all opacity-100 scale-100" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-100 scale-100" aria-hidden="true" style="flex-shrink: 0;"><path d="M12.5 3C13.3284 3 14 3.67157 14 4.5V6H15.5C16.3284 6 17 6.67157 17 7.5V15.5C17 16.3284 16.3284 17 15.5 17H7.5C6.67157 17 6 16.3284 6 15.5V14H4.5C3.67157 14 3 13.3284 3 12.5V4.5C3 3.67157 3.67157 3 4.5 3H12.5ZM14 12.5C14 13.3284 13.3284 14 12.5 14H7V15.5C7 15.7761 7.22386 16 7.5 16H15.5C15.7761 16 16 15.7761 16 15.5V7.5C16 7.22386 15.7761 7 15.5 7H14V12.5ZM4.5 4C4.22386 4 4 4.22386 4 4.5V12.5C4 12.7761 4.22386 13 4.5 13H12.5C12.7761 13 13 12.7761 13 12.5V4.5C13 4.22386 12.7761 4 12.5 4H4.5Z"></path></svg></div><div class="absolute inset-0 flex items-center justify-center"><div class="transition-all opacity-0 scale-50" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-0 scale-50" aria-hidden="true" style="flex-shrink: 0;"><path d="M15.1883 5.10908C15.3699 4.96398 15.6346 4.96153 15.8202 5.11592C16.0056 5.27067 16.0504 5.53125 15.9403 5.73605L15.8836 5.82003L8.38354 14.8202C8.29361 14.9279 8.16242 14.9925 8.02221 14.9989C7.88203 15.0051 7.74545 14.9526 7.64622 14.8534L4.14617 11.3533L4.08172 11.2752C3.95384 11.0811 3.97542 10.817 4.14617 10.6463C4.31693 10.4755 4.58105 10.4539 4.77509 10.5818L4.85321 10.6463L7.96556 13.7586L15.1161 5.1794L15.1883 5.10908Z"></path></svg></div></div></div></button></div></div><div class="overflow-x-auto"><pre class="code-block__code !my-0 !rounded-lg !text-sm !leading-relaxed p-3.5" style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono);"><code style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono); white-space: pre-wrap;"><span><span>$ du -sh ~/Library/Application\ Support/Claude/vm_bundles
</span></span><span> 12G /Users/jas/Library/Application Support/Claude/vm_bundles</span></code></pre></div></div>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">On a 16GB RAM machine, this creates significant resource pressure.</p>
<h3 class="text-text-100 mt-2 -mb-1 text-base font-bold">Issue 3: Persistent Freezing Pattern</h3>
<ul class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2">App has been freezing repeatedly since ~February 16, 2026 (coincides with the update that changed VM boot behavior)</li>
<li class="whitespace-normal break-words pl-2">Freezing occurs during Cowork sessions</li>
<li class="whitespace-normal break-words pl-2">After force-quitting and relaunching, various error messages appear</li>
<li class="whitespace-normal break-words pl-2">Problem persists through: full app reinstall, system reboot, clearing local-agent-mode-sessions data, clearing vm_bundles/Cache/Code Cache directories</li>
</ul>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Process Data at Time of Failure</h2>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Claude Desktop processes running during the failed session:</p>
<div class="overflow-x-auto w-full px-2 mb-6">
Process | CPU % | Memory (RSS)
-- | -- | --
Claude (main) | 5.5–7.2% | 139–186 MB (fluctuating)
Claude Helper (Renderer — Cowork UI) | 0.0% | 123–280 MB (spiking)
Claude Helper (Renderer) | 0.0% | ~65 MB
Claude Helper (Renderer) | 0.0% | ~65 MB
Claude Helper (Network) | 0.0% | ~55 MB
Claude Helper (GPU) | 0.0% | ~70 MB
Claude Helper (Audio) | 0.0% | ~38 MB

</div>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]"><strong>Notable:</strong> The Cowork renderer process spiked from 123MB to 280MB and back, suggesting it was loading and then crashing.</p>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Feature flags from the renderer process confirm Cowork VM is active:</p>
<div class="relative group/copy bg-bg-000/50 border-0.5 border-border-400 rounded-lg"><div class="sticky opacity-0 group-hover/copy:opacity-100 top-2 py-2 h-12 w-0 float-right"><div class="absolute right-0 h-8 px-2 items-center inline-flex z-10"><button class="inline-flex
items-center
justify-center
relative
shrink-0
can-focus
select-none
disabled:pointer-events-none
disabled:opacity-50
disabled:shadow-none
disabled:drop-shadow-none border-transparent
transition
font-base
duration-300
ease-[cubic-bezier(0.165,0.85,0.45,1)] h-8 w-8 rounded-md active:scale-95 backdrop-blur-md Button_ghost__BUAoh" type="button" aria-label="Copy to clipboard" data-state="closed"><div class="relative"><div class="transition-all opacity-100 scale-100" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-100 scale-100" aria-hidden="true" style="flex-shrink: 0;"><path d="M12.5 3C13.3284 3 14 3.67157 14 4.5V6H15.5C16.3284 6 17 6.67157 17 7.5V15.5C17 16.3284 16.3284 17 15.5 17H7.5C6.67157 17 6 16.3284 6 15.5V14H4.5C3.67157 14 3 13.3284 3 12.5V4.5C3 3.67157 3.67157 3 4.5 3H12.5ZM14 12.5C14 13.3284 13.3284 14 12.5 14H7V15.5C7 15.7761 7.22386 16 7.5 16H15.5C15.7761 16 16 15.7761 16 15.5V7.5C16 7.22386 15.7761 7 15.5 7H14V12.5ZM4.5 4C4.22386 4 4 4.22386 4 4.5V12.5C4 12.7761 4.22386 13 4.5 13H12.5C12.7761 13 13 12.7761 13 12.5V4.5C13 4.22386 12.7761 4 12.5 4H4.5Z"></path></svg></div><div class="absolute inset-0 flex items-center justify-center"><div class="transition-all opacity-0 scale-50" style="width: 20px; height: 20px; display: flex; align-items: center; justify-content: center;"><svg width="20" height="20" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg" class="transition-all opacity-0 scale-50" aria-hidden="true" style="flex-shrink: 0;"><path d="M15.1883 5.10908C15.3699 4.96398 15.6346 4.96153 15.8202 5.11592C16.0056 5.27067 16.0504 5.53125 15.9403 5.73605L15.8836 5.82003L8.38354 14.8202C8.29361 14.9279 8.16242 14.9925 8.02221 14.9989C7.88203 15.0051 7.74545 14.9526 7.64622 14.8534L4.14617 11.3533L4.08172 11.2752C3.95384 11.0811 3.97542 10.817 4.14617 10.6463C4.31693 10.4755 4.58105 10.4539 4.77509 10.5818L4.85321 10.6463L7.96556 13.7586L15.1161 5.1794L15.1883 5.10908Z"></path></svg></div></div></div></button></div></div><div class="text-text-500 font-small p-3.5 pb-0">json</div><div class="overflow-x-auto"><pre class="code-block__code !my-0 !rounded-lg !text-sm !leading-relaxed p-3.5" style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono);"><code class="language-json" style="color: rgb(20, 24, 31); background: transparent; font-family: var(--font-mono); white-space: pre;"><span><span class="token token" style="color: rgb(184, 10, 24);">"yukonSilver"</span><span class="token token" style="color: rgb(20, 24, 31);">:</span><span> </span><span class="token token" style="color: rgb(43, 48, 59);">{</span><span class="token token" style="color: rgb(184, 10, 24);">"status"</span><span class="token token" style="color: rgb(20, 24, 31);">:</span><span> </span><span class="token token" style="color: rgb(0, 128, 0);">"supported"</span><span class="token token" style="color: rgb(43, 48, 59);">}</span><span class="token token" style="color: rgb(43, 48, 59);">,</span><span>
</span></span><span><span></span><span class="token token" style="color: rgb(184, 10, 24);">"yukonSilverGems"</span><span class="token token" style="color: rgb(20, 24, 31);">:</span><span> </span><span class="token token" style="color: rgb(43, 48, 59);">{</span><span class="token token" style="color: rgb(184, 10, 24);">"status"</span><span class="token token" style="color: rgb(20, 24, 31);">:</span><span> </span><span class="token token" style="color: rgb(0, 128, 0);">"supported"</span><span class="token token" style="color: rgb(43, 48, 59);">}</span></span></code></pre></div></div>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Troubleshooting Already Attempted</h2>
<ol class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2">✅ Full reinstall of Claude Desktop</li>
<li class="whitespace-normal break-words pl-2">✅ System reboot</li>
<li class="whitespace-normal break-words pl-2">✅ Cleared <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">~/Library/Application Support/Claude/local-agent-mode-sessions/</code> contents</li>
<li class="whitespace-normal break-words pl-2">✅ Cleared <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">~/Library/Application Support/Claude/vm_bundles</code></li>
<li class="whitespace-normal break-words pl-2">✅ Cleared <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">~/Library/Application Support/Claude/Cache</code></li>
<li class="whitespace-normal break-words pl-2">✅ Cleared <code class="bg-text-200/5 border border-0.5 border-border-300 text-danger-000 whitespace-pre-wrap rounded-[0.4rem] px-1 py-px text-[0.9rem]">~/Library/Application Support/Claude/Code Cache</code></li>
<li class="whitespace-normal break-words pl-2">✅ Verified no VPN or antivirus interference</li>
<li class="whitespace-normal break-words pl-2">✅ Verified 80GB free disk space</li>
<li class="whitespace-normal break-words pl-2">❌ Cannot roll back to pre-Feb 16 version (no Time Machine, no old installer available)</li>
</ol>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Related Issues</h2>
<ul class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2">#26302 — Cowork VM boots on every launch even when unused, consuming background resources (same VM behavior, Windows)</li>
<li class="whitespace-normal break-words pl-2">#22543 — Cowork feature creates 10GB VM bundle that severely degrades performance</li>
<li class="whitespace-normal break-words pl-2">#23830 — Claude Cowork conflict with macOS 26 (vsock timeout issues)</li>
<li class="whitespace-normal break-words pl-2">#26087 — Cowork VM Kernel Panic Deadlocks Main Thread</li>
</ul>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Impact</h2>
<p class="font-claude-response-body break-words whitespace-normal leading-[1.7]">Cowork is completely unusable. I rely heavily on Cowork with custom skills and plugins for daily operations work. This is blocking all Cowork-dependent workflows.</p>
<h2 class="text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold">Suggested Fixes</h2>
<ol class="[li_&]:mb-0 [li_&]:mt-1 [li_&]:gap-1 [&:not(:last-child)_ul]:pb-1 [&:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-1 pl-8 mb-3">
<li class="whitespace-normal break-words pl-2"><strong>Don't start the Cowork VM unless the user opens a Cowork session</strong> — the VM currently boots on every launch even when unused</li>
<li class="whitespace-normal break-words pl-2"><strong>Investigate the API 500 errors</strong> occurring during workspace setup — the request ID is provided above for server-side debugging</li>
<li class="whitespace-normal break-words pl-2"><strong>Reduce VM bundle size</strong> or implement incremental updates rather than re-downloading 12GB on every clean install</li>
<li class="whitespace-normal break-words pl-2"><strong>Provide a version rollback mechanism</strong> — there is currently no way for users to return to a working version when updates introduce regressions</li></ol>

What Should Happen?

Expected Behavior
Cowork workspace should set up fully, accept tasks, and run without freezing or API errors.

Actual Behavior
Issue 1: API 500 Internal Server Error
Cowork returns the following error, sometimes while the workspace is still setting up (observed at 85% setup):
API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CYFn7QMyPcrNmWWz9K8GR"}
Followed by:
⚠ This task didn't load properly
API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CYFn7QMyPcrNmWWz9K8GR"}
Issue 2: 12GB VM Bundle on Clean Install
Immediately after a fresh install and first Cowork launch, the VM bundle grows to 12GB:
$ du -sh ~/Library/Application\ Support/Claude/vm_bundles
12G /Users/jas/Library/Application Support/Claude/vm_bundles
On a 16GB RAM machine, this creates significant resource pressure.
Issue 3: Persistent Freezing Pattern

App has been freezing repeatedly since ~February 16, 2026 (coincides with the update that changed VM boot behavior)
Freezing occurs during Cowork sessions
After force-quitting and relaunching, various error messages appear
Problem persists through: full app reinstall, system reboot, clearing local-agent-mode-sessions data, clearing vm_bundles/Cache/Code Cache directories

Error Messages/Logs

Process Data at Time of Failure
Claude Desktop processes running during the failed session:
ProcessCPU %Memory (RSS)Claude (main)5.5–7.2%139–186 MB (fluctuating)Claude Helper (Renderer — Cowork UI)0.0%123–280 MB (spiking)Claude Helper (Renderer)0.0%~65 MBClaude Helper (Renderer)0.0%~65 MBClaude Helper (Network)0.0%~55 MBClaude Helper (GPU)0.0%~70 MBClaude Helper (Audio)0.0%~38 MB
Notable: The Cowork renderer process spiked from 123MB to 280MB and back, suggesting it was loading and then crashing.
Feature flags from the renderer process confirm Cowork VM is active:
json"yukonSilver": {"status": "supported"},
"yukonSilverGems": {"status": "supported"}
Troubleshooting Already Attempted

✅ Full reinstall of Claude Desktop
✅ System reboot
✅ Cleared ~/Library/Application Support/Claude/local-agent-mode-sessions/ contents
✅ Cleared ~/Library/Application Support/Claude/vm_bundles
✅ Cleared ~/Library/Application Support/Claude/Cache
✅ Cleared ~/Library/Application Support/Claude/Code Cache
✅ Verified no VPN or antivirus interference
✅ Verified 80GB free disk space
❌ Cannot roll back to pre-Feb 16 version (no Time Machine, no old installer available)

Related Issues

#26302 — Cowork VM boots on every launch even when unused, consuming background resources (same VM behavior, Windows)
#22543 — Cowork feature creates 10GB VM bundle that severely degrades performance
#23830 — Claude Cowork conflict with macOS 26 (vsock timeout issues)
#26087 — Cowork VM Kernel Panic Deadlocks Main Thread

Impact
Cowork is completely unusable. I rely heavily on Cowork with custom skills and plugins for daily operations work. This is blocking all Cowork-dependent workflows.

Steps to Reproduce

Clean install Claude Desktop (or reinstall after removing previous version)
Open Claude Desktop
Switch to Cowork tab
Workspace setup begins ("Setting up Claude's workspace...")
Submit a task before or shortly after workspace setup completes
Observe API 500 error and "This task didn't load properly" message
App becomes unresponsive/freezes, requiring force quit
On relaunch, various error messages appear

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.7

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_

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