When you say "some of the features," are they specific things like videos that might require a plugin or other component? Is there a problem with making a secure connection or with glitchy graphics? Please be as specific as possible.

When you have a problem with one particular site that previously worked normally, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes. If you do not see the number going down on the page, you can reload it using Ctrl+r to check progress.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "View Cookies"
• (menu bar) Tools > Page Info > Security > "View Cookies"
• click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "View Cookies" button

In the dialog that opens, the current site should be pre-filled in the search box at the top of the dialog so you can remove that site's cookies individually.

Then try reloading the page. Does that help?

Yesterday I had a helluva time posting items for sale in groups. I could only do batch posting 3 or 4 at a time and sometimes that didn't work. After struggling to get my items posted for sale I noticed that the section called "your sale posts" is no longer there. This section allows you to manage your posts...edit, mark sold and view a list of your sold items. It's a major pia not to have that feature. I've asked around and no one else seems to have the problem. I am using FBPurity but that has nothing to do with this issue.

It's news to me: I didn't realize Facebook let you post things for sale!

Does that area show up when you check the page in other browsers?

If Yes:

Could you test in Firefox's Safe Mode? Steps will be below the line.

If No:

Maybe it's in Group Settings? But this is over a year old now so things may have changed: https://www.facebook.com/help/community/question/?id=1563679897245945

In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

I can't post the group to a browser. And, yes you can sell in FB's sale groups. I belong to several in my area. I get absolutely no help from FB.

Let me follow up on past questions/suggestions:

(1) Does the missing feature appear when you view your FB page in other browsers, such as Internet Explorer? If you removed the icon, you can go to the Start menu Run box and paste iexplore.exe and submit that and Windows should start it up.

(2) Did clearing cache and cookies in Firefox make any difference?

(3) Did Firefox's Safe Mode make any difference?

It didn't surprise me that FB didn't work at all in IE. And, no the others didn't resolve it either. I do have a message into FBs help center but I won't hold my breath that I'll get a response although I must say they jumped right on the issue when my page was hacked and someone posed as me and then contacted all of my female friends and became a perv from hell

One other thing you could try while you wait for any authoritative explanation is to use a fresh Firefox profile.

New Profile Test

This takes about 3 minutes, plus the time to test Facebook.

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

Click the Create a New Profile button, then click Next. Assign a name like Aug2016, ignore the option to relocate the profile folder, and click the Finish button.

After creating the profile, scroll down to it and click the Set as default profile button below that profile, then scroll back up and click the Restart normally button.

Firefox should exit and then start up using the new profile, which will just look brand new.

Does your Facebook page work any better in the new profile?

When you are done with the experiment, open the about:profiles page again, click the Set as default profile button for your normal profile, then click the Restart normally button to get back to it.