Troubleshooting

When Cowork won't cooperate.

Every tool has a bad day. Here are the Cowork errors people run into most, what's actually going wrong under the hood, and the fastest way back to work.

macOS · Windows

Claude Cowork Not Working? Start Here

Cowork stuck, won't open, or just not doing anything useful? This triage guide covers the top six failure modes and walks you to the right fix fast.

cowork not workingcowork won't opencowork stuck

Read the fix → macOS · Windows

Permission Denied: Why Cowork Can't Access Your Files (and How to Fix It)

Claude Cowork says it can't read or write your folder? Here's why macOS and Windows block it, and the exact steps to fix each cause.

Cowork says it cannot read the folderFile access denied error when writingNo permission to write to folder

Read the fix → macOS · Windows

Failed to Start Workspace: Claude Cowork Cannot Connect

Claude Cowork showing 'failed to start workspace' or 'workspace still starting'? Here is why it happens and how to fix it on macOS and Windows.

failed to start workspaceworkspace still startingcannot connect to Claude API

Read the fix → macOS · Windows

MCP Connection Failed: Fixing Broken Connectors and Tool Connections in Cowork

Cowork can't connect to a tool or MCP server? Here's how to diagnose and fix connector failures, expired auth, bad configs, and server problems.

Connector shows as disconnected or unavailableMCP server error when using a toolTool not available in Cowork session

Read the fix → macOS · Windows

Context Window Exceeded: What to Do When Cowork Chokes on Too Many Files

Cowork hit its token limit on a big PDF or folder? Here's what the context window actually is, why it fills up, and practical ways to work around it.

Error says the prompt is too longCowork stops mid-task after reading many filesPDF too large to process

Read the fix → macOS · Windows

Sub-Agent Timeout: Why Your Parallel Agents Never Finish

Parallel sub-agents hanging forever in Claude Cowork? Here are the real causes and step-by-step fixes that actually work, without restarting from scratch.

task hangsagents never finishspinner forever

Read the fix →

Still stuck?

Two things worth trying before anything else.

Update the Claude desktop app, then fully quit and reopen it. A surprising number of Cowork problems trace to an old build or a session that needs a clean restart. If that fails, check Anthropic's status page to rule out an outage, then read the specific fix above. The official starting point is the Claude help center.