When a Squarespace site appears as "Not Secure" in a web browser, it usually indicates that the connection between the website and the user’s browser is not encrypted. Here’s a breakdown of why this might happen and how to resolve it:

1. SSL Certificate Issues

SSL (Secure Sockets Layer) Certificates are crucial for securing data exchanged between a user’s browser and your website. Most commonly, a site showing "Not Secure" is experiencing issues related to SSL.

Potential Issues and Solutions:

• SSL Certificate Not Provisioned: Squarespace provides free SSL certificates that are automatically provisioned. Sometimes, provisioning may fail.

• Solution: Ensure your domain's DNS settings are correctly configured and point to Squarespace. The SSL may take up to 72 hours to provision. Go to the Home Menu > Settings > Domains > SSL Settings and confirm that SSL is enabled.

• Expired SSL Certificate: Although Squarespace usually handles SSL renewals, sometimes manual intervention may be required.

• Solution: Contact Squarespace support to inquire about the status of the SSL certificate and whether it needs renewal.

2. Mixed Content

A site may have mixed content issues when it loads both secure (HTTPS) and non-secure (HTTP) resources.

Potential Issues and Solutions:

• HTTP Links in Content: Sometimes, images, scripts, or stylesheets are linked using HTTP instead of HTTPS.

• Solution: Review your site's content to ensure all internal resources use HTTPS. Modify any URLs pointing to HTTP manually.

• External Resources: If your site loads resources (like fonts, scripts, or widgets) from external sources via HTTP.

• Solution: Check with the external resource provider if HTTPS is available and update your links accordingly or switch to secure alternatives.

3. Domain Settings

Improper domain settings might also cause security issues.

Potential Issues and Solutions:

• Incorrect DNS Settings: Ensure your domain’s DNS settings match those provided by Squarespace exactly.
• Solution: In the Home Menu, navigate to Settings > Domains, and verify your DNS settings. Squarespace offers step-by-step guidance to confirm settings are correct.

4. Browser and Caching

Sometimes, the issue might be due to local browser caching or the user’s device.

Potential Issues and Solutions:

• Cached HTTP Version: If a browser has cached the non-secure version of your site, it might keep displaying it.
• Solution: Clear the browser cache or try accessing your site in an incognito/private window. You can also suggest visitors do the same.

5. Certificate Warnings

Browsers display certain warnings for websites with SSL certificates that are not recognized by trusted authorities or have been misconfigured.

Potential Issues and Solutions:

• Unrecognized Certificate Authority: Ensure that no custom SSL certificates are interfering, as these might not be recognized by all browsers.
• Solution: Stick with the SSL certificates provided by Squarespace unless you have a good understanding of custom SSL configurations.

Practical Steps to Ensure Your Site is Secure:

1. Verify Domain Connection: Make sure your domain is correctly connected to Squarespace.
2. Check SSL Status: Go to Settings > Domains and ensure SSL is set to "Secure."
3. Fix Mixed Content: Use tools like WhyNoPadlock or built-in developer tools in browsers to identify mixed content issues and update all resources to HTTPS.
4. Regular Monitoring: Periodically check your site security status to ensure ongoing encryption.

Limitations to Consider:

• Delayed SSL Provisioning: Sometimes generating an SSL certificate from Squarespace’s end can take longer due to several factors like domain propagation delays.
• External Dependencies: If your site relies heavily on external scripts or resources, ensuring they all support HTTPS can be challenging.

If these steps don’t resolve the issue, contacting Squarespace’s support team would be a prudent next step. They can provide more personalized assistance and investigate any deeper technical issues that may be affecting your SSL status.