=== Tool Bars Customize Firefox controls, buttons and toolbars {web link}

Type about:customizing<enter> in the address box.

Note: about:customizing is no longer present in Firefox v47+ releases.

• Press Alt or F10 to bring up the Menu Bar. Then View > Toolbars >
• Right-click on a blank spot on the toolbar and select what you want.
• Right-click on a blank spot on the toolbar and select Customize Toolbar.
  Look for Show / Hide Toolbars or just Toolbars at the bottom left.
  There is also a Restore Defaults button at the bottom right.

=== Icons Customize Firefox controls, buttons and toolbars {web link}

Type about:customizing<enter> in the address box.

Note: about:customizing is no longer present in Firefox 47+ releases.

• Press Alt or F10 to bring up the Menu Bar.Then View > Toolbars > Customize.
• Right-click on a blank spot in the toolbar and select Customize.

In the new window, look for the icon. When you find it, hold down the left button on it, and move it to where you want it to be. You can move any of the icons you want from here, but; some icons are locked in place.

There is also a Restore Defaults button at the bottom right.

If you have sync, and there is a problem anywhere, Shut Down Sync Immediately On All Devices to prevent the problem from spreading. Type https://accounts.firefox.com/settings<enter> in the address box. Once the problem is fixed, perform the same repair on all computers/profiles before using sync again.

[v57+] Places Maintenance is built into Firefox.

Type about:support<enter> in the address box.

You will find Places Database near the bottom. Press the Verify Integrity button.

If any errors are reported: https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional

The places.sqlite and favicons.sqlite files contains your History and Bookmarks. And it looks like they are corrupted.

Type about:support<enter> in the address box.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the above files. Then rename or delete them. Restart Firefox. The browser should then create a new place.sqlite and recover your bookmarks from the backup files.

Note: Your history is not backed up and will be lost.