{ Ctrl + B } does open the Bookmarks Sidebar. Might you be using that key combination for something else or using it inadvertently?

Or hitting the Show Sidebars button in the user interface? Which will default to the last used "sidebar" of the three that are available - Bookmarks, History, and Synced Tabs.

Nothing else is using the same key combination and no the keys are not sticking....I have tried a different keyboard but still the same.....This is driving me mental AS a matter of interest, aearch on Google brings up the same complaint from 2005......It wasn't solved then either....

Let's try Firefox in Safe Mode, to see if maybe one of your extensions (if you have any) could be causing this :

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

If Firefox is running : 3-bar menu => ' ? ' (at the bottom of the dropdown) => 'Restart with Add-ons disabled'. Then OK the restart. A small dialog should appear. Click 'Start in Safe Mode' ( not 'Refresh' !)

See : https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

Started doing it again.....still does it in safe mode ....

What Firefox locale (user interface) language do you use in case your specific locale has an issue?

English UK

You may have set certain bookmarks to open in the sidebar :

In the Library (Ctrl + Shift + b) you can click on the 'More' button at the bottom of the page. Make sure that "Load this bookmark in the sidebar" is not selected.

In case you use a mouse - it's also available if you: • right-click the bookmark on the Bookmarks menu or Bookmarks toolbar • click Properties • then look to the bottom of the Properties dialog for the checkbox

Nope good try but no cigar

scouseken said

Nope good try but no cigar

Bummer  !

You shouldn't smoke anyway .....

Giving it another shot - would you try this :

Rename or remove the xulstore.json file in the Firefox profile folder.

Go to the 3-bar menu => Help (at the bottom) => Troubleshooting Information. Under 'Application Basics' : Scroll down to 'Profile Folder' and click on 'Open Folder'.

That may have done the trick....however I shall wait and see if it starts asgain like it did before///

Anyway Thanks a million

scouseken said

That may have done the trick....however I shall wait and see if it starts asgain like it did before///

Keeping my fingers crossed ......

Started playing up again this morning....AAAAARRRRGGGGHHHHH

Did you already update to Firefox 61.0.1?

You can create a new profile to test if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox