Hi

This support article should help:

https://support.mozilla.org/en-US/kb/bookmarks-firefox

When I click on the star at the end of the address bar, nothing happens (the star doesn't even turn blue)

Don't stop helping me!

Hi,

Another way to create a bookmark is right-clicking the Bookmarks Toolbar and selecting Add Bookmark... Could you please try that?

Bookmarks Toolbar doesn't have Add Bookmark..

Are you sure you are clicking the Bookmarks Toolbar? You may need to show it first. See the article for details.

Near the top of the Firefox page is displayed:

The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can caused this problem.

In such a case, please check out Fix "The bookmarks and history system will not be functional" error message.

I deleted all of the favicons and places files.

After I restarted Firefox:

1) the missing History and Bookmarks had been restored 2) the "The bookmarks and history system will not be functional..." error message was no longer displayed