known issue mcp writes

Known Issue: Claude Desktop File Writes Failing Silently

Claude Desktop sometimes reports that it successfully created or wrote a file in the vault, but the file never actually appears in Obsidian or Finder. This is a confirmed bug in Claude Desktop, not a problem with our setup.

What Happens

You ask Claude to save something to the knowledge base
Claude says it wrote the file successfully
The file does not appear in Obsidian or Finder
Reads (listing directories, reading existing files) may still work normally in the same conversation

Why It Happens

This is a confirmed Claude Desktop bug (GitHub Issue #15060). Certain conversation threads enter a corrupted state where MCP tool calls are never actually sent to the server, even though Claude generates output that looks like they succeeded. Once a thread is in this state, it cannot recover.

Workarounds (Until Anthropic Fixes It)

1. If a conversation stops writing files, start a new one

The corruption is per-conversation. Opening a fresh conversation restores normal MCP functionality. If you suspect a write didn’t go through, don’t keep retrying in the same conversation.

2. Always verify writes

After any write operation, ask Claude to read the file back:

“Read the file you just created at [path]”

If the MCP connection is actually broken, the read will also fail or return suspicious results. If the file reads back correctly, the write was real.

3. Check Obsidian or Finder directly

The simplest check: look for the file in Obsidian’s file explorer or in Finder. If it’s not there within a few seconds of Claude reporting success, the write didn’t go through. Start a new conversation and try again.

Signs That a Conversation May Be Broken

Claude claims to write a file but it doesn’t appear
Claude gives you file contents that seem plausible but don’t match what’s actually in the file
You see “MCP call failed” briefly during Claude’s thinking, followed by it claiming success anyway

Last updated: 2026-02-19