Go to ≡ -> Customize and seek for the NewTab icon.

Eventually click the Restore Defaults button

Hi TyDraniu, Thank you for that - it did help - in a way. Oeriginally I was able to open or add extra tabs by clicking on a + button at the RH end of my open tabs. That option is not there anymore but I have added the 'Open a new tab' icon as you suggested. It works but is still tecnically a workaround but thank you anyway. Kind regards Andrew

But you can place this button on the rh end of the tab bar.

The plus button to open a new tab would normally snap directly after the last tab. In customize mode it will appear at the left of the list all tabs button at the at the right end of the Tab bar, but it should move to the position right after the last tab once you close the Customize window. You can drag this button to the far left or far right or to another toolbar in customize mode. If you do not see the plus icon in customize mode then click the Restore Defaults button like posted above.

• https://support.mozilla.org/en-US/kb/customize-firefox-controls-buttons-and-toolbars
• https://support.mozilla.org/en-US/kb/navigation-buttons-missing

Thank you all for your help, in the end I did a Restore & the button reappeared.

Many thanks