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

# Resolving WebAssembly Errors on iOS

> Guide to resolving 'WebAssembly not found' errors on iOS devices

If you encounter a "WebAssembly not found" error when using ID Check on iOS devices, follow these troubleshooting steps in order.

## Understanding the Problem

This error occurs when WebAssembly functionality is blocked by iOS security settings or browser environment. In particular, when **Lockdown Mode** is enabled, WebAssembly execution is forcibly blocked in Safari, causing a `ReferenceError: Can't find variable: WebAssembly` error. Check each method below one by one.

## Solutions

### 1. Check and Disable Lockdown Mode

If Lockdown Mode is enabled on iOS 16 or later, WebAssembly will be blocked. Lockdown Mode is hidden at the bottom of the menu due to its high security level.

<Steps>
  <Step title="Open Settings app">
    Open the **Settings** app on your iPhone.
  </Step>

  <Step title="Navigate to Privacy & Security">
    Select the **Privacy & Security** menu.
  </Step>

  <Step title="Scroll to the bottom">
    Scroll to the **very bottom (all the way down)** of the screen.
  </Step>

  <Step title="Check Lockdown Mode">
    Find the **Lockdown Mode** option at the bottom of the **Security** section and check its current status.
  </Step>

  <Step title="Disable Lockdown Mode">
    If Lockdown Mode is set to **On**, tap the toggle to change it to **Off**.
  </Step>
</Steps>

<Info>
  **If the Lockdown Mode menu is not visible:**

  * **Check iOS version**: Lockdown Mode is only supported on iOS 16 or later. If you're using iOS 15 or earlier, this menu will not appear. (You can check your version in Settings > General > About)
  * **Device restrictions**: In rare cases, if your device is managed by a company or school with an MDM (Mobile Device Management) profile installed, certain security settings may be restricted and the menu may not be visible.
</Info>

<Tip>
  If you need to keep Lockdown Mode enabled for security reasons, you can exclude the ID Check site from Lockdown Mode in Safari's website settings. Open the site in Safari, tap the **aA** icon next to the address bar, then select **Website Settings** and choose to exclude it from Lockdown Mode.
</Tip>

<Warning>
  Lockdown Mode is a security-enhancing feature. Be aware of security risks after disabling it.
</Warning>

<Frame caption="iOS Settings > Privacy & Security > Security section showing Lockdown Mode location">
  <img src="https://mintcdn.com/argosidentity/SxZLC1cexuVA2rhg/images/camera_permission/lockdown_mode.png?fit=max&auto=format&n=SxZLC1cexuVA2rhg&q=85&s=a7f0fa7a2e3ab0a60590b9162b4a01f4" alt="iOS Settings showing Lockdown Mode in Privacy & Security section" width="760" height="920" data-path="images/camera_permission/lockdown_mode.png" />
</Frame>

### 2. Open in Safari Browser Directly

Issues may occur when using in-app browsers or apps added to the home screen.

<Steps>
  <Step title="Open Safari browser">
    Launch the **Safari** app directly on your iPhone.
  </Step>

  <Step title="Enter URL in address bar">
    Enter the full address of the ID Check page in Safari's address bar.
  </Step>

  <Step title="Retry the page">
    Refresh the page or start over from the beginning.
  </Step>
</Steps>

<Tip>
  WebAssembly may not work in browsers opened from within apps like KakaoTalk, Facebook, or Instagram. Try opening the page directly in the Safari app.
</Tip>

### 3. Check Safari Experimental Features

WebAssembly may be disabled in Safari's experimental features settings.

<Steps>
  <Step title="Open Settings app">
    Open the **Settings** app on your iPhone.
  </Step>

  <Step title="Navigate to Safari">
    Select the **Safari** menu.
  </Step>

  <Step title="Select Advanced">
    Select the **Advanced** menu at the bottom of the screen.
  </Step>

  <Step title="Check Experimental Features">
    Select the **Experimental Features** menu.
  </Step>

  <Step title="Verify WebAssembly">
    Find the **WebAssembly** item in the list and verify it is set to **On**.
  </Step>
</Steps>

<Info>
  WebAssembly is enabled by default in most recent iOS versions. However, if it was manually changed previously, you may need to verify this setting.
</Info>

### 4. Check iOS Version

WebAssembly is only supported on iOS 11 or later.

<Steps>
  <Step title="Open Settings app">
    Open the **Settings** app on your iPhone.
  </Step>

  <Step title="Select General">
    Select the **General** menu.
  </Step>

  <Step title="Check About">
    Select the **About** menu.
  </Step>

  <Step title="Check Software Version">
    Check your current iOS version in the **Software Version** item.
  </Step>
</Steps>

<Warning>
  If you're using iOS 10 or earlier, you need to update iOS. Go to **Settings > General > Software Update** to proceed with the update.
</Warning>

### 5. Clear Cache and Data

The issue may be caused by browser cache or stored data.

<Steps>
  <Step title="Open Safari settings">
    Go to **Settings > Safari**.
  </Step>

  <Step title="Clear History and Website Data">
    Select **Clear History and Website Data**.
  </Step>

  <Step title="Confirm">
    Select **Clear** in the confirmation message.
  </Step>

  <Step title="Retry the page">
    Open Safari again and reload the ID Check page.
  </Step>
</Steps>

## If the Problem Persists

If you've tried all the methods above and the problem still persists:

1. **Restart device**: Turn off your iPhone completely and turn it back on.
2. **Restart Safari app**: Completely close the Safari app and launch it again.
3. **Check network**: Verify you're using a stable Wi-Fi or cellular connection.

<Note>
  In most cases, disabling Lockdown Mode or opening the page directly in Safari browser resolves the issue. If the problem persists, please contact customer support.
</Note>