What causes "No file storage format with key "%s" exists." in phacility/phabricator?

phacility/phabricator · error · Exception

No file storage format with key "%s" exists.

Error message

No file storage format with key "%s" exists.

What it means

PhabricatorFileStorageFormat::requireFormat() throws when no storage format class is registered under the given format key. Format keys are FORMATKEY class constants discovered via PhutilClassMapQuery, so an unknown key means a typo or a format class that is not loaded (disabled module, removed custom class). Reads and writes of files can both route through this lookup.

Source

Thrown at src/applications/files/format/PhabricatorFileStorageFormat.php:76

  }

  final public static function getAllFormats() {
    return id(new PhutilClassMapQuery())
      ->setAncestorClass(__CLASS__)
      ->setUniqueMethod('getStorageFormatKey')
      ->execute();
  }

  final public static function getFormat($key) {
    $formats = self::getAllFormats();
    return idx($formats, $key);
  }

  final public static function requireFormat($key) {
    $format = self::getFormat($key);

    if (!$format) {
      throw new Exception(
        pht(
          'No file storage format with key "%s" exists.',
          $key));
    }

    return $format;
  }

}

View on GitHub (pinned to 5720a38cfe)

Solutions

List registered keys and fix the typo: var_dump(array_keys(PhabricatorFileStorageFormat::getAllFormats())) — expected keys include 'raw', 'test', 'aes-256-cbc'
If old files reference a removed custom format, restore or re-enable that class (e.g. via a Phabricator module) so the key resolves again
Correct files.default-format to a key that exists on this install

Example fix

// before
$format = PhabricatorFileStorageFormat::requireFormat('aes-256-cbc-256');

// after
$format = PhabricatorFileStorageFormat::requireFormat('aes-256-cbc');

Defensive patterns

Strategy: validation

Validate before calling

// Soft-resolve before requiring:
if (PhabricatorFileStorageFormat::getFormat($format_key) === null) {
  // Unknown format key: choose from the registered set instead of letting
  // requireFormat() throw mid-request.
  $valid = implode(', ', array_keys(PhabricatorFileStorageFormat::getAllFormats()));
  throw new Exception("Unknown storage format '{$format_key}'. Valid: {$valid}");
}

Type guard

function isValidStorageFormatKey($key) {
  return array_key_exists($key, PhabricatorFileStorageFormat::getAllFormats());
}

Prevention

Derive format keys from class constants, e.g. PhabricatorFileAES256StorageFormat::FORMATKEY, instead of string literals
Keep custom storage format classes enabled on every install that holds files referencing their keys
Add a deploy-time check that files.default-format resolves via getFormat()

When it happens

Trigger: Calling PhabricatorFileStorageFormat::requireFormat('aes-256-bcb') with a typo; files.default-format set to a key with no matching class; loading a file row whose storage format references a custom format class that is no longer enabled on this install.

Common situations: Renaming or deleting a custom storage format class while old files still reference its key; typo'd config values; moving a database to an install that lacks the extension providing the format.

Related errors

AI-assisted analysis of phacility/phabricator@5720a38cfe (2026-08-21). Data as JSON: /api/errors/6777a18b8faef5b6. Report an issue: GitHub.