ERROR - "Failed to send prompt. Unexpected server error. Check server logs for details."

[wndrzzka]

Description

An "Unexpected server error" occurs when trying to send prompts using the DeepSeek V4 Flash model.
Error message text: "Failed to send prompt. Unexpected server error. Check server logs for details."

OpenCode version

1.17.20

Steps to reproduce

1. Open VS Code with OpenCode CLI integrated.
2. Select the model: DeepSeek V4 Flash.
3. Type any prompt in the terminal/chat panel (e.g., "p" or "payment gateway...").
4. Press enter to send, and the error appears instantly.

Operating System

Windows 10

Terminal

Windows Terminal

[github-actions]

This issue doesn't fully meet our contributing guidelines.

What needs to be fixed:

• The Description field contains only "Error when entering the prompt" — please include the actual error message text, not just a vague summary
• Steps to reproduce only contains an image; please describe what you were doing step-by-step and include the error message as text so it can be searched and indexed
• Please clarify: what model/provider were you using, and what were you typing in the prompt when this occurred?

Please edit this issue to address the above within 2 hours, or it will be automatically closed.

If you believe this was flagged incorrectly, please let a maintainer know.

[github-actions]

Thank you for updating the issue! It now meets our contributing guidelines. We appreciate you taking the time to provide the error message text, steps to reproduce, and your system details.

[wndrzzka]

Update: It seems the issue is not isolated to the DeepSeek V4 Flash model. Changing to other available models in the CLI results in the exact same "Unexpected server error", suggesting a broader server-side or gateway issue.

[wndrzzka]

Update:
I found that this issue is isolated to this specific chat session.

• Creating a new chat session works perfectly fine without any errors.
• The error only persists in this current session (which has around 193k tokens, though it hasn't exceeded my token limits).
• It seems to be a session-specific crash or state issue rather than a global server downtime.

[sebastianlungu]

+1 got this as well

[DavLink]

I got this. In my case I changed the directory by mistake. Moving the session to the actual project folder fixed it. Hope it helps somebody.