I was updating firefox other day and after the update i have found the tabs gone back to default location. I like tabs after web address bar. So, here is how it can be changed if you need.
- On your firefox browser write about:config and press enter.
- You will be shown a alert message. Click “I will be careful, Promise!”.
- write browser.tabs.onTop on search bar.
- You should be seen filtered settings. There should be only one. Double click it. and you are done. Close the browser.
Let me know if its worked for you.