[BUG] /schedule skill consistently fails with "trouble connecting with your remote claude.ai account"

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?

The /schedule skill (scheduled-tasks MCP) fails every time I try to create a new scheduled task, returning:

We're having trouble connecting with your remote claude.ai account to set up a scheduled task. Please try /schedule again in a few minutes.

What Should Happen?

Scheduled task registers successfully.

Error Messages/Logs

Error message above, no task created.

Steps to Reproduce

Invoke /schedule with any task spec
Skill attempts to register the trigger on claude.ai
Returns the error above

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.63 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Description
The /schedule skill (scheduled-tasks MCP) fails every time I try to create a new scheduled task, returning:

We're having trouble connecting with your remote claude.ai account to set up a scheduled task. Please try /schedule again in a few minutes.

Reproduction

Invoke /schedule with any task spec
Skill attempts to register the trigger on claude.ai
Returns the error above
Attempts
Tried 5 times over roughly an hour, including:

Short retries (~5 min apart)
Longer gap (~30 min)
With only one Claude Code session running
History
I've successfully created scheduled tasks in the past (had a daily email briefing task that I deleted recently). Task creation has never worked since.

Environment

Claude Code on macOS (Darwin 25.2.0)
Model: Opus 4.7
Expected
Scheduled task registers successfully.

Actual
Error message above, no task created.