AdguardTeam/AdGuardHome · error

filters: at index %d: expected object, got %T

Error message

filters: at index %d: expected object, got %T

What it means

During migration to schema 29, an element of the filters array is not a YAML object. Each filter must be a mapping so its url field can be inspected (and rewritten if it's an absolute local path); scalars or nested arrays abort the migration.

Source

Thrown at internal/configmigrate/v29.go:46

//	    - '/path/to/file.txt'
//	  # …
func (m Migrator) migrateTo29(_ context.Context, diskConf yobj) (err error) {
	diskConf["schema_version"] = 29

	filterVals, ok, err := fieldVal[[]any](diskConf, "filters")
	if !ok {
		return err
	}

	paths := []string{
		filepath.Join(m.dataDir, "userfilters", "*"),
	}

	for i, v := range filterVals {
		var f yobj
		f, ok = v.(yobj)
		if !ok {
			return fmt.Errorf("filters: at index %d: expected object, got %T", i, v)
		}

		var u string
		u, ok, _ = fieldVal[string](f, "url")
		if ok && filepath.IsAbs(u) {
			paths = append(paths, u)
		}
	}

	fltConf, ok, err := fieldVal[yobj](diskConf, "filtering")
	if !ok {
		return err
	}

	fltConf["safe_fs_patterns"] = paths

	return nil
}

View on GitHub (pinned to b41aefbe51)

Solutions

1. Rewrite every filters entry as a mapping with url/enabled keys
2. Delete malformed entries that aren't real filter definitions
3. Re-run Migrate

Example fix

# before
filters:
  - https://example.org/hosts

# after
filters:
  - enabled: true
    url: https://example.org/hosts

for _, f := range filters {
    if _, ok := f.(map[string]any); !ok { /* rewrite as {url: ..., enabled: true} */ }
}

func isFilterObj(v any) bool { _, ok := v.(map[string]any); return ok }

if err != nil && strings.Contains(err.Error(), "expected object, got") { /* convert bare-string filters to objects and retry */ }

When it happens

Trigger: Migrating a config where filters contains a non-object entry, e.g. `- https://example.org/hosts` (bare string) instead of `- url: https://example.org/hosts, enabled: true`.

Common situations: Hand-converted configs where filter URLs were written as plain list items; merging filter lists from different sources with inconsistent shapes.

Related errors

• unexpected type of upstream field: %T
• persistent client at index %d: unexpected type %T
• unexpected type of %q: %T
• parsing config file for upgrade: %w
• generating new config: %w

AI-assisted analysis of AdguardTeam/AdGuardHome@b41aefbe51 (2026-08-27). Data as JSON: /api/errors/1bc71f88617cd8cd. Report an issue: GitHub.