Hi, do you mean the + button that's usually on the tab bar -- it's missing?

That button can be moved, for example, onto the main toolbar or somewhere else. If you call up the Customize tab, you can look for it and drag it back, or check the box of available/unused buttons to see whether it is in there. If all else fails, there is a "Restore defaults" button to roll the toolbars back to their original "factory" layout. More info:

Customize Firefox controls, buttons and toolbars

I tried customize, the only + is in zoom controls. restore defaults just gets rid of my toolbar. box of available unused buttons I cant find. This is why I hate updates.

I guess there is no box, it's just the whole left-center section of Customize.

After using Restore Defaults, could you launch a new window (Ctrl+n) to see whether the + button appears on the tab bar there?

In case there is a theme/color problem where the + is not visible against the background color, try hovering the mouse next to the last tab on the tab bar and see whether the button is highlighted or the tooltip appears. This is the "Light" theme on Windows 10, for example:

Can you attach a screenshot?

• https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem
• use a compressed image type like PNG or JPG to save the screenshot

ok-found it there were two issues the new tab button moved from the left to the far right corner and it was grayed out!

Hmm, it shouldn't be grayed out. Does it work now?

works now. I think it was a combination of theme/color & moving to upper right corner. Don't know why it did that, problem was in win7, I'm in win10 now running same firefox v83 & its in its normal place.

I had the same problem in ver 84 , found the + tab all the way to the right on the toolbar. I right clicked on it and deleted it and it appeared back where it was just to the right of the last tab showing