Hi dsig, that's troubling.

At startup, do any of the restore options work? For example:

Restore Previous Session

• "3-bar" menu button > Restore Previous Session
• (menu bar) History > Restore Previous Session

Reopen Closed Windows

• "3-bar" menu button > Library > History > Recently Closed Windows
• "Library" toolbar button > History > Recently Closed Windows
• (menu bar) History > Recently Closed Windows

Is your Firefox saving history normally? You can check it using either the sidebar (Ctrl+h) or library window (Ctrl+Shift+h). Do URLs get added as your browse? Is older history intact?

Regarding this --

the google home page no longer shows al my 'tiles' of most active sites. Some have dropped of and others do not show the sites.

-- I think you mean the built-in Firefox Home / new tab page with a Google search box, and not a page on Google's site.

It's certainly possible for tiles to drop out of the top 8 or top 16 if you visited some other site more often recently. It list is weighted between frequency and recency. You could increase the number of tiles to see whether the site you're interested in moved further down the list. There is a selector for that on the Options page in the section discussed in this article: Customize your New Tab page to hide or display content.

If Firefox can't generate a thumbnail image for a page, hmm, I'm not sure what could cause that.

If you use Sync then best is to disconnect Sync temporarily during troubleshooting.

This issue can be caused by a problem with the places.sqlite and favicons.sqlite databases in the Firefox profile folder.

• use "Verify Integrity" button on the "Help -> Troubleshooting Information" (about:support) page

If 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 Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data