Hi there! I understand you’re having some trouble with Norton blocking the Universe web app on your Mac. Let's work through this together to find a solution.

1. Check Norton Alerts: First, can you tell me if you received a specific alert message from Norton? Sometimes it clarifies why a site is blocked, which can give us clues on how to proceed.

2. Norton Application Blocking: If the alert indicates it’s an application blocking issue, we can adjust those settings. Here’s how you can potentially resolve it:
- Open Norton on your Mac.
- Navigate to your Settings.
- Look for Firewall settings, and check under Application Blocking.
- If you find the Universe app listed there, remove the rule blocking it, then add it back again. This can often clear up false positives.

3. Safe Web Feature: If it's a web page being blocked:
- Open Norton and go to the Safe Web feature.
- You might need to check if the setting is turned on for blocking dangerous sites. Sometimes, disabling it temporarily can help you access the site to verify if it’s safe.

4. Whitelist the URL: If you’re sure it's a safe site, you can add the Universe web app to Norton’s exceptions:
- Navigate to Settings > Firewall > Traffic Rules.
- Then add the URL of the Universe app to the exceptions list.

If the issue persists after trying these steps, let me know, and I can help you delve deeper into this, or we could consider contacting Norton support for further assistance. Are you satisfied with this information, or do you have any more details to share?