So when you start up Firefox you have your homepage come up is what you want is that correct or the 2nd tab to open you want a copy of your homepage ? https://support.mozilla.org/en-US/kb/how-to-set-the-home-page

If you want the 2nd tab to open to another URL put a Vertical Line ( | ) in at the end of the 1st URL and then the next URL and 2 tabs will open at start up.

Not to sure what your trying to accomplish here...

I hope that you use separate profiles for each Firefox version. If you didn't do this then you should create a new profile at least for Nightly.

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

You posted with a Firefox 60 user agent. Is that Firefox 60.1.0 ESR?

The New Tab Override extension works for me in Nightly.

• New Tab Override
  https://addons.mozilla.org/firefox/addon/new-tab-override/

Do you see on "Options/Preferences -> Home" that the NTO extension wants to override the new tab page?

My real user agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0 But I use chameleon to spoof it. I can't install New Tab Override https://i.imgur.com/CHk739C.png Also I don't think it's ESR because I installed it with `sudo apt-get install firefox-trunk` if I remember well. I don't know what are the profile, I will check this. Pkanswer, I want to see my homepage instead of a blank page when I open a new tab

The profile don't change anything

And I said my user agent is Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0 but it's false. I don't know my user agent and I don't think it's useful

TheDevKiller said

I want to see my homepage instead of a blank page when I open a new tab

Probably a very dumb question, but why don't you just press Ctrl + the Home icon  ?

Hmm it's a little boring but why not. If you have another solutions you always can say that but I will use this as temporally solution or more if I need

And also, It's weird that I can't install New Tab Override, I have a good version (<61)

TheDevKiller said

And also, It's weird that I can't install New Tab Override, I have a good version (<61)

I just went over everything it says under 'About this extension' and I can't find anything there that might shine a light on it .....

Maybe you could post a question here :

https://github.com/cadeyrn/newtaboverride/issues

Ok I will do this later

It is best not to spoof the user agent when you try to install an extension as this might confuse the Addons website.

With my real User Agent, Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0, I have the same message (on Firefox Stable 62) :/

In fact, New Tab Homepage works but not with a local file :/

TheDevKiller said

Also I don't think it's ESR because I installed it with `sudo apt-get install firefox-trunk` if I remember well.

If you want to be a Nightly channel Tester then you should use the official Nightly channel builds from Mozilla and not third-party packages that may introduce their own issues on top of any issues occurring due to being a work in progress. The Nightly channel is more for Testers and Devs as it gets checkins and updates twice a day and issues can occur until fixed, finished or reverted.

https://www.mozilla.org/firefox/nightly/all/

And if you want to be a Nightly channel tester then a place to check out is the Builds threads in http://forums.mozillazine.org/viewforum.php?f=23 as some Tester hang out there and threads make it easy to see the changes.

You can't set the new tab page to a local file or about page when you use an extension. You can only use internet pages (http: or https:).

So I can use localhost, I think I will make a web server on my PC. I know it's overkill but if it's the only solution ...

It works :) ! Thank you !