gofiber/fiber · error

failed to render: %w

Error message

failed to render: %w

What it means

The configured template engine (app.Config.Views, e.g. html/pongo/jet from gofiber/template) returned an error rendering 'name' with bind and the given layouts. The wrapped error comes from the engine and typically means 'template not found', 'template syntax error', or a missing referenced layout.

Source

Thrown at res.go:769

	var rendered bool
	for _, prefix := range slices.Backward(rootApp.mountFields.appListKeys) {
		app := rootApp.mountFields.appList[prefix]
		if prefix == "" || strings.Contains(r.c.OriginalURL(), prefix) {
			if len(layouts) == 0 && app.config.ViewsLayout != "" {
				layouts = []string{
					app.config.ViewsLayout,
				}
			}

			// Render template from Views
			if app.config.Views != nil {
				if err := func() error {
					viewsLock := getViewsLock(app.config.Views)
					viewsLock.RLock()
					defer viewsLock.RUnlock()

					if err := app.config.Views.Render(buf, name, bind, layouts...); err != nil {
						return fmt.Errorf("failed to render: %w", err)
					}

					return nil
				}(); err != nil {
					return err
				}

				rendered = true
				break
			}
		}
	}

	if !rendered {
		// Render raw template using 'name' as filepath if no engine is set
		var tmpl *template.Template
		if _, err := readContent(buf, name); err != nil {
			return err

View on GitHub (pinned to 9a4c7e57fe)

Solutions

1. Verify the template name matches a template the Views loader can resolve (check the loader root and extension).
2. Ensure app.Config.Views is set and the engine is loaded (e.g. html.New("./views", ".html")).
3. Check that any referenced layout exists and templates have no syntax errors.

Example fix

// before
app := fiber.New() // Views not configured
c.Render("index", data) // failed to render: template not found

// after
engine := html.New("./views", ".html")
app := fiber.New(fiber.Config{Views: engine})
c.Render("index", data)

// at startup, assert the engine loaded the templates you expect
if err := engine.Load(); err != nil {
    log.Fatalf("views load failed: %v", err)
}

if err := c.Render(name, bind, layouts...); err != nil {
    log.Errorf("render %q failed: %v", name, err)
    return c.Status(fiber.StatusInternalServerError).SendString("render error")
}

When it happens

Trigger: c.Render("user.tmpl", data) where user.tmpl does not exist in the Views loader, has a syntax error, or references a layout file that is missing; or Views was not set on the app.

Common situations: Wrong template name/path; template file deleted or not embedded in the build; ViewsLayout configured but layout file absent; engine loaded with the wrong directory.

Related errors

• logtemplate: unknown tag
• failed to open: %w
• failed to read: %w
• failed to parse: %w
• failed to execute: %w

AI-assisted analysis of gofiber/fiber@9a4c7e57fe (2026-08-04). Data as JSON: /data/errors/8b5d77ae66664e8a.json. Report an issue: GitHub.