I've got pop-up windows open in new tabs in Firefox, and scrolling works fine this way.

Open about:config.

Search for: Change its value to 0.

May need a browser restart to take effect.

Huh...that's weird. I'm pretty sure i set that to 0 some time ago. Forgot to check that earlier though....
That fixed it though.

Edit: Oh well - just remembered that i set that on my old computer not on this one :)

I put such changes in my user.js file, and back it up, then just put it in every new profile I create for whatever reason. Saves me the trouble of having to go through about:config manually each time.

I usually forget because i use FF sync for the backup and i usually only need to adjust the about:config on my Linux systems :)
But thanks for pointing me in the right direction and for the useful tip :)

Thanks for the update !
It seems to work well in Palemoon, except that I encountered same problem than ElTerprise : missing scroll-bar of the changelog (which is opened in a new window).
I did the change suggested by HypersomniacLive, and it's opening now changelogs in a new tab, with a functioning scroll-bar :)
Thanks HypersomniacLive too so :)

Great, glad it works in Palemoon too :)

I've put in a fix for the scroll bars, but it will need to wait for the next update to go live.

:)
Yay ! I'll tell you if the fix works well ;)

Does not work for me. I can still scroll using keyboard but not with the mouse since there are no scroll bars in the changelog popup. Any other ideas?

I also noticed that there does not seem to be a changelog entry for Witcher 3 and we all know that this game had some biiig changelogs.

Are you saying you've followed the instructions I gave, restarting your browser, and the changelog still opens in a pop-up window instead of a new tab?

That's odd, can you check in your prefs.js file in your profile if the following is in there? If you can't get this to work, then wait for adaliabooks' fix.

As for TW3 - it's the known issue of IDs mismatch, adaliabooks is working on a solution.

I'll get the fix sorted after the weekend and it shouldn't be a problem for anyone then.

That's a separate issue, Witcher 3 (along with quite a few other games) has a different ID in the catalogue and library so the changelog doesn't load properly. I'm trying to figure out the best way to deal with these cases.

Yes to all. Just tried it again: opens in a popup window with no scrollbars and the entry in the prefs.js is definitely there.

That's pretty odd. What version of Firefox are you on? And what are the values of these about:config entries?

FF 42.0
browser.link.open_newwindow = 2
browser.link.open_newwindow.override.external = -1

Dare I ask why you're still on Firefox 42.0 when the latest stable version is 47.0?

Change the value of from 2 to 3, and try again. May require a browser restart to take effect.

I clicked the "search for updates" button prior to posting this and nothing happened. So my FF obviously thought to be up to date. Will check this as well as the newwindow entry. Be back in a bit.

Edit: changing the value did the trick - thank you. So can you also tell me, why my FF is not updating even though I have activated automatic updates?