---
title: "Web Vision | Startup Template | N3uron KB V1.22"
slug: "web-vision-viewer-startup-template"
description: "Set the Web Vision startup template in the Designer to define the initial screen loaded by the Viewer when users open your HMI and SCADA application."
updated: 2026-10-08T09:06:04Z
published: 2026-10-08T09:06:04Z
canonical: "docs.n3uron.com/web-vision-viewer-startup-template"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.n3uron.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Startup Template

The **Startup Template** defines the initial template that **Web Vision** loads when the project Viewer is launched. It provides the entry point for the runtime interface and determines what users see first when opening the HMI in **Viewer**. The Startup Template is marked with an asterisk (*****) in the **Project Tree**.

This page explains what the Startup Template is, how it is marked in the project, and what happens if no Startup Template has been defined.

## **How to Mark a Startup Template**

The Startup Template is marked from the project structure in **Designer**. The selected template becomes the default entry point used by **Viewer** when the project is loaded.

1. Open the Web Vision project in **Designer**.
2. Locate the template that should be used as the project entry point.
3. Open the template options or context menu.
4. Select the option to mark the template as the **Startup Template**.
5. Save the project and validate the result in **Viewer**.

A single Startup Template can be defined at a time, meaning that selecting a new template as Startup when other template is marked will replace the one existing in first place.

![](https://cdn.document360.io/54093ab5-6b22-4542-a265-04377931f11a/Images/Documentation/SetStartup.png)

> [!NOTE]
> **Tip:**
> 
> Use a main layout or application shell as the Startup Template when the project contains multiple screens. This makes navigation and screen loading easier to control.

The same procedure can be followed to unset a template as Startup template. By doing this, no entry point is specified on Viewer, showing an error popup on **/ui** page until a new Startup template is defined.

![](https://cdn.document360.io/54093ab5-6b22-4542-a265-04377931f11a/Images/Documentation/UnsetStartup.png)

## **What Happens If No Startup Template Exists?**

If no Startup Template is defined, **Viewer** does not have a clear entry point for the project. As a result, the project may not open the expected HMI screen or may show an empty, incomplete, or invalid startup state depending on the project configuration.

![](https://cdn.document360.io/54093ab5-6b22-4542-a265-04377931f11a/Images/Documentation/OpenUIUnsetStartup(3).png)

| **Condition** | **Possible result** |
| --- | --- |
| **Startup Template defined** | **Viewer** opens the configured template as the initial runtime view. |
| **Startup Template missing** | **Viewer** may not know which template to load first, causing an empty, unexpected, or incomplete startup experience. |
| **Startup Template deleted** | The project should be reviewed and another valid template should be marked as the Startup Template. |

> [!WARNING]
> **Recommendation:**
> 
> Always define one Startup Template before publishing or validating the project in **Viewer**. This avoids runtime ambiguity and ensures that users open the intended HMI entry point.

## **Recommended Startup Template Structure**

The Startup Template should usually contain the global structure of the HMI rather than a single isolated component. This makes it easier to control navigation, shared layout, and screen loading.

| **Condition** | **Suggestion** |
| --- | --- |
| **Main header** | Displays project title, status, user information, or global indicators. |
| **Navigation area** | Provides access to the main screens, dashboards, equipment views, or menus. |
| **Content area** | Loads the default dashboard or the first operational view. |
| **Shared components** | Includes common popups, alarm summaries, side panels, or reusable project elements. |

[**Web Vision Full Product Details**](https://n3uron.com/iiot-platform-modules/web-vision/)