[BUG] Getting "invalid_request_error" when typing '/context' command in middle of claude code session in Thinking mode

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?

When I try to check the context of my current load code session while I am developing, using the /context command, I get the below message ( this is specifically true just for when 'thinking' is on.)

⎿ Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.123.c
    ontent.0.type: Expected `thinking` or `redacted_thinking`, but found `text`. When `thinking`
     is enabled, a final `assistant` message must start with a thinking block (preceeding the 
    lastmost set of `tool_use` and `tool_result` blocks). We recommend you include thinking 
    blocks from previous turns. To avoid this requirement, disable `thinking`. Please consult 
    our documentation at https://docs.claude.com/en/docs/build-with-claude/extended-thinking"},"
    request_id":"req_011CUhtTvqWjcnrbX8LXg49b"}

Steps to reproduce error:

1. Start a Claude Code session and try to work on an existing application or build a new application.
2. After a couple of messaging back-and-forth, type /context command in Claude Code session while thinking mode is on.

What Should Happen?

Claude should provide the output for the context command as it does when the thinking mode is off.

Error Messages/Logs

> /context 
  ⎿ Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.123.c
    ontent.0.type: Expected `thinking` or `redacted_thinking`, but found `text`. When `thinking`
     is enabled, a final `assistant` message must start with a thinking block (preceeding the 
    lastmost set of `tool_use` and `tool_result` blocks). We recommend you include thinking 
    blocks from previous turns. To avoid this requirement, disable `thinking`. Please consult 
    our documentation at https://docs.claude.com/en/docs/build-with-claude/extended-thinking"},"
    request_id":"req_011CUhtTvqWjcnrbX8LXg49b"}

Steps to Reproduce

Steps to reproduce error:

1. Start a Claude Code session and try to work on an existing application or build a new application.
2. After a couple of messaging back-and-forth, type /context command in Claude Code session while thinking mode is on.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.31 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_