Diễn đàn hỗ trợ Firefox

I'm using the OneTab add-on, Enabled. The icon no longer shows on the Toolbar, though it is on the Menu bar next to Firefox View.

I ran Remove and then Added it again, hoping the Toolbar Icon would reappear = no go, And I lost all URLs already saved, stupid me. To be clear, clicking the Icon on the Toolbar saves all open tabs.

Is there a fix via Preferences? Thanks. gw

My Windows 10 PC stopped working a few days & is disconnected & partially disassembled. I’m temporarily using an old Windows 7 PC which I brought up from the basement the following day. They both have Firefox on them.

I saved one bookmark on the Win7 PC today. It was there when I looked earlier. Now I went to use it again & it’s not there. But my Win10 bookmarks are there!!

How could that be?