Hi! I understand you're seeing an HTTP Strict Transport Security (HSTS) error when accessing Power Planner on Firefox on your Mac. Let's get you back to using the app smoothly.

HSTS is a security feature that forces browsers to connect only via HTTPS for a site. Sometimes, if there's a certificate or connection mismatch, Firefox blocks access with an HSTS error.

To resolve it, here’s what I'd recommend:

1. Clear Firefox’s HSTS Settings for Power Planner domain
- Close all Firefox windows.
- Open Firefox fresh.
- Press Cmd + Shift + H to open History.
- Search for the Power Planner website domain in your history.
- Right-click on the entries for that site and choose “Forget About This Site.” This clears cached cookies, HSTS settings, and site data for that domain.

2. Check Firefox Security Settings
- In the URL bar, type about:config and press Enter.
- Accept the warning to proceed.
- In the search bar on that page, type security.enterprise_roots.enabled and ensure it's set to true. If not, double-click to toggle it on. This allows Firefox to trust certificates added at the OS level.

3. Restart Firefox after these changes and try accessing Power Planner again.

4. Confirm System Date and Time on your Mac are accurate, as incorrect time can cause TLS/HTTPS certificate errors.

5. If you have any antivirus or firewall software installed, try temporarily disabling it to check if it is interfering with HTTPS connections.

If the error persists despite these steps, it might be related to a server-side certificate issue or network configuration, in which case I can assist further or help you contact Power Planner support.

Would you like me to guide you through any of these steps? Also, have you tried any fixes already? That way, I can tailor the guidance further.

power planner on firefox giving message about HTTP HSTS and not having a secure connection

Thanks for sharing that the Firefox browser on your Mac is showing an HTTP Strict Transport Security (HSTS) error with no secure connection specifically when trying to access Power Planner. That gives us a clearer picture.

Based on what I see, a common cause for this Firefox HSTS error is interference from security or antivirus software that tampers with HTTPS connections, causing certificate issues. Additionally, cached HSTS settings in Firefox or incorrect system date/time can contribute.

Here’s a tailored step-by-step approach for your macOS 10.15 environment:

1. Temporarily disable antivirus or security software
Some apps like Avast or AVG can interfere with secure connections by inspecting HTTPS traffic and cause HSTS errors. If you have any such apps running, try disabling them temporarily and then accessing Power Planner again.

2. Clear HSTS settings and site data for Power Planner in Firefox
- Open Firefox.
- Click the menu button (three horizontal lines) > History > Manage History.
- Search for Power Planner's website domain.
- Right-click the domain entries and choose “Forget About This Site.” This clears all cached data including HSTS flags2.

3. Verify system date and time
On your Mac, click the Apple menu > System Preferences > Date & Time. Make sure the date and time are correct and set to update automatically. Incorrect time can cause HTTPS certificate errors9.

4. Check Firefox settings for trusted certificates
- Type about:config in Firefox’s address bar and press Enter.
- Accept the warning.
- Search for security.enterprise_roots.enabled and ensure it is set to true. This allows Firefox to trust certificates installed at the OS level which might help in recognizing your network security certificates.

5. Restart Firefox and try accessing Power Planner again.

If after these steps the issue persists, it could indicate a problem with the Power Planner site’s SSL certificate or your network environment blocking secure traffic, and I’d be happy to help coordinate further troubleshooting or contacting Power Planner support.

Does this plan make sense? Would you like me to walk you through any step in detail?