[BUG] Linebreak in input window causes send of message

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?

Earlier I could use Shift-Enter to make a linebreak in the message I am writing in Claude.ai (using desktop app for Apple).

But since a few hours back, that does not work and it causes the message to be sent.

What Should Happen?

Shift enter gives you a line break in the message that is written. It does NOT send the message.

Error Messages/Logs

Steps to Reproduce

1. Open Claude App.
2. Write a message, try making a line break with Shift-Enter

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.1.2685 (f39a62) 2026-02-10T19:42:56.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

_No response_