Troubleshooting
What Studio's common failures actually mean, starting with the one that produces no useful message at all.
"An error occurred" in the Playground
The most common failure, and the least informative. In practice it is almost always one of three things, in this order of likelihood.
1. The model no longer exists. The gateway advertises several retired models, and they sort to the top of the dropdown, so the default choice is frequently a broken one. The underlying message is "This model is no longer available" — Studio does not surface it.
Switch the Agent component to Nufi-lab/models/gemini-2.5-flash or
gemini and run again. The full list is in
Connect a model.
2. No model provider is configured. A fresh instance has none. The canvas says so on a new flow — "Add a model provider" — but an existing flow just fails. Check Settings → Model Providers: a configured provider sits at the top of the list with a model count beside it.
3. A component input is empty. Expand the error row with the chevron; when it is a component problem the message usually names the input.
The flow runs but ignores my documents
Retrieval returned nothing useful. Run the retrieval step on its own and look at what came back before blaming the prompt — see Knowledge.
I cannot create an API key
If you signed in through NuFi and key creation is refused, the instance is configured to deny API keys to members who arrive that way — the reasoning being that a key outlives the session and does not carry the access level. An administrator can change it. A local Studio account is unaffected.
Saving a Credential variable fails
If the message mentions a Fernet key, the instance's encryption key is not valid and no credential can be stored. This is a deployment problem — see Installing NuFi Studio.
My flow disappeared after a redeploy
Studio's default database is a file inside the container, which does not survive one. A correctly deployed instance points at PostgreSQL. If flows vanish on deploy, that is what to check — and it needs an administrator.
The first page load is slow
The service sleeps when idle and takes a few seconds to wake. Subsequent loads are fast. Worth opening it once before a demo.