Is Your DeepSeek Harness Error a Missing Credential or Unknown Model?

1. Record the DeepSeek Harness model error before editing anything

Begin with the message actually shown, not the fix suggested by the first search result. Save the error code and a short description of the action that triggered it. Was it a model-list request, the first chat message, or an existing session that had previously worked?

Keep this note local while you inspect it for secrets. Replace a private provider label with “provider-A” and use that replacement consistently. Preserve the difference between two providers if it matters. A useful record names the action and error; it does not need your account key.

2. Follow the credential branch only for a credential problem

The upstream model guide (opens in a new tab) maps MISSING_CREDENTIAL to saving the provider key through the Models page or supplying the referenced environment variable. UNKNOWN_MODEL instead calls for a configured model. These messages identify different configuration checks.

For a credential error, confirm that you are looking at the provider selected for the failing request. A key saved for one provider does not establish that another provider is configured. If an administrator manages the environment, ask them to verify the required credential reference without sending you the secret.

Do not print an environment variable or copy a credentials file into a troubleshooting message. Record only whether the intended credential source is present. If you must update a key, use the documented configuration flow for your installed version, and keep that value out of the conversation.

3. Check the model identifier and its provider together

For UNKNOWN_MODEL, compare the selected identifier with the models configured under that provider. Similar display names can hide different identifiers. Copy the non-sensitive model identifier carefully when it is public; describe or consistently redact it when it reveals a private deployment.

For a custom gateway, consult its own documentation or administrator about the identifier it accepts. Do not substitute a model name from an unrelated tutorial. Write down what you changed, such as “selected an existing model under provider-A,” rather than claiming the endpoint was repaired.

The upstream guide (opens in a new tab) also distinguishes new-session defaults from the model retained by a session that has already made a request. Check the failing session itself instead of assuming a changed default rewrites it.

4. Separate discovery results from a chat result

A failed model-list request and a failed conversation are separate observations. Label which action produced each error. For example, “listing failed; chat not tested” is more useful than “the provider is down.” Avoid drawing conclusions about service availability from one local configuration.

Use the DeepSeekDSH error center (opens in a new tab) to locate the matching error category, then compare its instructions with upstream documentation and your version. This community index can help you choose a diagnostic branch; it does not verify your account or endpoint.

If the message changes after a fix, save it and reconsider the diagnostic branch. Do not keep replacing credentials simply because the previous error involved them.

5. Retry once with a controlled, non-sensitive request

Choose an isolated disposable workspace and a short text-only request requiring no repository access, edits or commands. Keep the provider, model and wording stable while changing one relevant setting. “Reply with the word ready” is an example test, not evidence of a passed setup.

• Record the selected provider and model before the retry.
• Record success or the exact redacted error afterward.
• If unresolved, preserve the smallest useful report and stop making unrelated changes.

Conclusion: keep the diagnosis narrower than the symptom

A DeepSeek Harness model error becomes easier to investigate when you separate credentials, model selection and the action that failed. Finish with an observed result and a redacted record. A successful response confirms that request, not the safety or reliability of a larger workflow.