Firefox 49+ multiprocess windows feature (e10s) is disabled by ubufox

[Marcos Felipe Mello]

Firefox 49+ enables e10s by default:

https://wiki.mozilla.org/Electrolysis

But Ubuntu's "Ubuntu Modifications 3.2" extension disables it. In about:support output it says:

"Multiprocess Windows 0/1 (Disabled by add-ons)"

If we manually disable "Ubuntu Modifications" extension, it works:

"Multiprocess Windows 1/1 (Enabled by default)"

I am using Xubuntu 16.04, firefox 49.0+build4-0ubuntu0.16.04.1, xul-ext-ubufox 3.2-0ubuntu1.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[B. C. Schmerker (bcschmerker)]

Prior to running:
sudo apt-get purge --remove xul-ext-ubufox
I ran into constant crashes with both Mozilla® Firefox® 48.0+build2-0ubuntu0.16.04.1 and 49.0+build4-0ubuntu0.16.04.1, extensions or no extensions. This may be related to Bug 1612994 "firefox crashes constantly", but don't yet know (as of 15 October 2016) whether 1612994 can be satisfactorily marked a duplicate of this Bug.

[Brausepaul (onlineguy)]

Bug still present with Firefox 50, the Ubuntu modifications are blocking the main Firefox improvement of the last releases.

[Mossroy (mossroy)]

I manually forced e10s on Firefox 50 (50.0.2+build1-0ubuntu0.16.04.1), and used it more than one week without noticeable issue.
So maybe the "Ubuntu modifications" extension is e10s-compatible, but simply not marked as such?

[Cavia Porcellus (caviaporcellus)]

I've also been using e10s for a few weeks now as well and can confirm are no noticeable bugs or issues. The Ubuntu modifications just need to be marked as compatible.

[Shu Hung (Koala) (koalay)]

I am using Firefox 49 and confirm to have this issue.

The page "about:support" shows "Multiprocess Windows" as "0/1 (Disabled by add-ons)".

[Shu Hung (Koala) (koalay)]

This issue cause problem with Firefox touch support (see my ticket here: https://bugzilla.mozilla.org/show_bug.cgi?id=1213342). Please take care of the issue. Thanks.

[Shu Hung (Koala) (koalay)]

Forgot to mention:

I'm using Ubuntu 16.10, ubufox 3.2 with Firefox 49.

[John Dennis (johndennis998)]

it affects me too.

ubuntu 16.04.2 LTS,ubufox 3.2 with firefox 52.0.2

[Diep Pham (favadi)]

I looks at the change log and seems that there is no development happens since Sep 2015. Maybe someone familiars with firefox extension development should step up and submit a patch?

[Robert Strube (robstrube)]

With Firefox 53.0 and 17.04 this is still happening. Only solution was to disable the "Ubuntu Modifications" extension. This is really unfortunate, as the default behavior for all new Ubuntu installations is for multi-processing to be disabled, which makes browsing slower and less responsive.

[Xristh (prflr)]

I'm trying firefox 57 from nightly builds and look like it don't allow the extensions to ever run and I thing ff55 released today do the same so...

we can up the prioroty? it a blocker for anything beyond ff55.