Hi Tom, the drop-down on the address bar can show many types of suggestions. Are they all failing, or only the suggestions from history? Here's an illustration of the different indications:

One possible and unfortunate reason for the drop-down to stop working is if Firefox can't access the Places database (places.sqlite file) normally. That's where both bookmarks and history are stored. Have you noticed any issues adding new bookmarks? If so, please try:

(1) Do a normal quit out of Firefox and shutdown/restart of your Mac.

(2) Run the "Verify Integrity" function.

Open Firefox's Troubleshooting Information page using any of these methods:

• "3-bar" menu button > "?" Help > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Return

Near the bottom, there is a section titled Places Database -- that's the file which stores history and bookmarks. Click the button labeled Verify Integrity. There may be a 10-15 second delay before results appear.

If all is well, the report that appears below the button should start with:

> Task: checkIntegrity
+ The places.sqlite database is sane
+ The favicons.sqlite database is sane

Does yours say that, or something else? You can select and copy the report, and then paste it into a reply for review and comment.

By the way, this article describes where to check and make sure that History, Bookmark, and Open Tab suggestions are enabled: Address bar autocomplete suggestions in Firefox.

Thanks for the fast answer, sorry to be so slow to get back to you. I just did what you suggested in Troubleshooting, and this is what I got as a response -

> Task: checkIntegrity - Unable to check places.sqlite integrity: Error: Error(s) encountered during statement execution: database disk image is malformed > Task: invalidateCaches - The task queue was cleared by an error in another task. > Task: checkCoherence - The task queue was cleared by an error in another task. > Task: expire - The task queue was cleared by an error in another task. > Task: originFrecencyStats - The task queue was cleared by an error in another task. > Task: vacuum - The task queue was cleared by an error in another task. > Task: stats - The task queue was cleared by an error in another task. > Task: _refreshUI - The task queue was cleared by an error in another task.

This means pretty much nothing to me, though the "database disk image is malformed" does not sound good. If you have any other help you can give me that would be great!

Thanks again!

In case errors are reported with "Verify Integrity" close and restart Firefox and retry.

If "Verify Integrity" cannot repair places.sqlite, rename/remove all places.sqlite and favicons.sqlite files in the Firefox profile folder. Firefox will rebuild places.sqlite and restore the bookmarks from a recent JSON backup in the bookmarkbackups folder.

• keep a backup copy of places.sqlite in case a new places.sqlite database has to be created

See also:

• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file
• https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/Profiles

Thanks very much! I renamed the places.sqlite and favicons.sqlite files as directed, then restarted Firefox and now the Search Suggestions is working again!

Any idea why this would have happened, or how I can keep it from recurring? Or is it just one of those things that can happen and needs to be dealt with when it does?

Thanks again for your help!