hello, what exactly have you done in about:config? please try right-clicking and resetting the browser.places.smartBookmarksVersion preference and restart the browser afterwards...

See also:

• https://support.mozilla.org/kb/Restore+the+default+Smart+Bookmarks+Folders

If you have accidentally removed bookmarks then use "Organize > Undo" in the bookmarks manager (Bookmarks > Show All Bookmarks) to get them back. That only works if you haven't closed Firefox.

Are you referring to one of the site thumbnails on the "new tab" page?

Some of the other responses related to the "Most Visited" smart bookmark folder which appears by default on the Bookmarks Toolbar. I think the two work independently.

Hello. Thanks for taking the time to answer my question.

In response to Philipp, yes, that is exactly what I did (following another firefox support article) and what I meant by 'following the procedure with about:config'. I right-clicked on browser.places.smartBookmarksVersion, chose 'reset', and then restarted the browser. But there was no change. The 'most visited' page was exactly the same as before, minus the button for the page I really wanted there. I restarted the browser by going to 'exit' and then later opening firefox again; did that perhaps not count as restarting it?

In response to Cor-el, I wish I'd known that before I closed firefox in order to follow the instructions relating to about:config!

The thing is, even going back to the page I want to reinstate over and over again doesn't seem to help, since once I've 'deleted' pages from the 'most visited' page they don't come back there even though I visit them constantly. What to do?

I reiterate that if the option of reinstating a former 'most visited' page doesn't exist, then the firefox/mozilla people should create it, especially since this 'deletion' appears to be irreversible! Surely an accident created by the exact opposite of its intent (clicking on the button to GO THERE, not to delete it - a vote of confidence, in other words) cannot be allowed to have irreversible consequences, in computers if not in life?

For the new tab page, did you find a menu with Undo or Restore All as described in this article?

https://support.mozilla.org/en-US/kb/new-tab-page-show-hide-and-customize-top-sites#w_remove-a-site

I noticed when I remove a thumbnail from the newtab page, two preferences get updated:

• browser.newtabpage.blocked
• browser.newtabpage.pinned

I suspect that right-click Reset on these will restore the newtab page to its original sequence, but I'm having mixed results. I might need to restart Firefox in order to get the page repopulated based on history.

Edit: Restarting Firefox seems necessary to get the newtab page regenerated after clearing the blocked and pinned preferences.

You can change the order of the boxes on the about:newtab page and drag an item to a different slot to pin it to that position or you can remove a website by clicking the close X to block that URL. You can drag a bookmark or history item and drop them in a slot on the about:newtab page to pin them and have your own favorites sites showing.

Changes made manually on the about:newtab page are stored in the browser.newtabpage.pinned (default = [null]) and browser.newtabpage.blocked prefs that you can check/modify on the about:config page.

If you have deleted the website in a tile manually then you can reset the browser.newtabpage.blocked pref via the right-click context menu to remove all blocks.

• http://kb.mozillazine.org/about:config

Hello, Jscher2000! Sorry, I hadn't seen your message because I think I posted my reply at the same time as you posted yours.

Anyway, yes, that worked! Thank you so much! Let's emphasise that this

https://support.mozilla.org/en-US/kb/new-tab-page-show-hide-and-customize-top-sites#w_add-a-site

is the procedure which solves this particular problem, in case others have the same difficulty.

I didn't find a 'restore all' or 'undo' button at the top of the page (as in 'remove a site'), but I was able to 'add' the relevant bookmark back into the page (as in the section 'add a site').

I think that confusion with terminology is part of the reason why I couldn't express the problem properly and hence couldn't search for the 'new tab page' as opposed to the 'toolbar' or 'folder' etc. So yes, it is the 'new tab page' that I was referring to. The page with all the little square images which lead to frequently visited websites.

Thanks again, and also thanks to the others who took the time to answer.

Cheers - Ants.