Anyone hitting the below error when running claude code?
⎿  API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"The request body is not valid JSON: invalid high surrogate in string: line 47 column 5162 (char 45482)"}}

I am getting excessive errors , such as:

⎿  API Error: 400 due to tool use concurrency issues. Run /rewind to recover the conversation.

Anyone else getting the same type of error. Using Claude 2.0.10 version.

Hey everyone,

I wanted to share a solution for a specific error I’ve been encountering in Claude Code. After using a session for a few hours, the conversation compaction fails, and I get locked out with this API Error 400:

Error: Error during compaction: Error: API Error: 400

{"type":"error","error":{"type":"invalid_request_error","message":"messages.7.content.1: \thinking` or `redacted_thinking` blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response."}}`

Simply closing the terminal or restarting didn't fix it for me immediately. However, I found a specific workflow that forces the compaction to go through.

The Solution:

1. Close the terminal completely.

2. Open a new terminal and run claude--resume and choose your conversation

3. When the error appears (or before you type anything else), change the model by typing /model

4. Then select sonnet 4.5

5. Send a simple prompt like: "What happened bro?"

6. This seems to force the conversation to compact successfully without the error.

7. Once the compaction is done, use /model again to switch back to your preferred model (eg. Opus 4.5) and continue coding.

I hope this saves someone the headache I went through these 3-4 days.