Diễn đàn hỗ trợ Firefox

My desktop Mac suddenly (July 28) quit displaying page specified fonts, in some - not all - instances, using Inspector reveals affected sites defaulting to Helvetica Last Resort, or failing to display Open Sans via gstatic.com. For comparison, my laptop - same FF v.78.12.0esr, using the same (advanced - default) fonts and colors settings - displays everything properly, as do those same sites on mobile. This is a local problem.

Those sites affected work fine using Chrome, Safari, which indicates system level fonts are loading properly.

Of the sites affected, one thing in common seems to be that they are WordPress/PHP dynamic sites.

I use FontExplorerX font management, which has been stable for years. There aren't any reported conflicts.

Application and system font caches have been flushed.

Firefox has been freshened.

I feel like this may be a corrupted prefs file somewhere, but have no idea how to proceed.

Attached images show different page display results using same search term in Google, DuckDuckGo, and two sites that are affected.

We are receiving this message from Ebay when attempting to list a product (see below). Any suggestions how to work around it please? Thank you.

Did Not Connect: Potential Security Issue

Firefox detected a potential security threat and did not continue to scgi.ebay.co.uk because this website requires a secure connection.

What can you do about it?

scgi.ebay.co.uk has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site.

The issue is most likely with the website, and there is nothing you can do to resolve it. You can notify the website’s administrator about the problem.

This past week I started getting the Did Not Connect: Potential Security Issue warning when I tried to access my email at Comcast.net. I also got the warning on my banks website when I tried to transfer funds, something I had done many times before. This seems to have started after "upgrading" to version 78.7.1 of FireFox. However, I got the same sort of error using Safari: "Safari can't verify the identity of the website xfinityconnect.email.comcast.net" The certificate shows it is issued by "AVG untrusted CA" from the country "CZ" and State/Province "Brno". Comcast told me to just trust their certificate and I was able to get to my email account, but I am getting the same warning from PNC Bank's website when I try to transfer funds. This REALLY has me worried. Can someone tell me if this is a sign I've been hacked? How can I fix this so I can again transfer funds from my checking account to other banks?

When I opened Firefox I received a "news message" that makes no sense to me. How can I revert Firefox to its former usefulness? There is something about the former installation of Firefox being undisturbed, but I cannot find that installation. Apparently this has something to do with sync-ing my desktop Firefox with other installations -- I've less than zero interest in sync-ing.

What happened to the bookmarks I had stored in the bookmark bar? How do I get those back?