Troubleshooting

What the usual messages mean and what to do.

On this page

Studio does not start

  • “KERVAN_STUDIO_MASTER_KEY is not set”: set it. If the message says the data directory already holds encrypted secrets, set the key it was set up with, not a new one.
  • “Secret X … cannot be decrypted”: the configured keys do not match the database. Set the right KERVAN_STUDIO_MASTER_KEY, and older ones in KERVAN_STUDIO_PREVIOUS_MASTER_KEYS.
  • “Kervan Studio needs Node.js …”: upgrade Node.js to 22.23.3 or a later 22.x, or 24.21.0 or later.
  • The port is in use: Studio says so in one line; set KERVAN_STUDIO_PORT.
  • A migration failed, or the database is newer: restore the backup made before the upgrade, or run the newer Studio.

The setup page cannot be reached

Before the first admin exists, Studio listens on 127.0.0.1 only. From another machine, or in a container, create the first admin with create-admin instead; see install.

Sign-in is refused

Five failed attempts for an account, or twenty from an address, lock it for 15 minutes. If an admin password is lost, use reset-admin on the host; a lock already in effect lasts until it expires or Studio restarts.

A client gets 401, 403 or 404

  • 401: the key is missing, wrong, revoked or for another server. The answer is the same for all four, on purpose.
  • 403: the request has an Origin that is not Studio’s public URL, or a Host that is not its host name. Check KERVAN_STUDIO_PUBLIC_URL and that the proxy keeps the Host header.
  • 404: the server is not published, disabled or deleted.

A publish is refused

The message lists each problem with its line. Usual causes: a secret the version uses does not exist, or may not be sent to the host a tool calls; a tool sends a secret to an http:// URL; a field is misspelled.