Plasma 5.11.3 breaks firefox

[Sergio Callegari]

After the delivery of plasma 5.11.3 via the kubuntu backports ppa (ppa:kubuntu-ppa/backports), firefox is completely unusable.

Seen on two different machines, one with intel graphics (haswell) and one with nvidia quadro FX570 using the nouveau driver.

Firefox cannot be used unless compositing is turned off in kwin, so I suspect an issue in the latter. Specifically, all firefox buttons that are expected to open a window (e.g., the main menu button, the bookmark button, most of the extensions button) do not, making the browser limited to mere browsing (no bookmarks, no advanced actions driven via the menu, no extensions).

The two machines where I see the issue have in common the use of mesa as the opengl provider (latest mesa in fact). I do not have the option to try with proprietary graphics drivers.

Please, provide a way to go back to 5.11.2 without removing the KDE backports altogether.

[Simon Quigley (tsimonq2)]

Thank you for taking the time to report this bug and helping to make Kubuntu better. We are sorry that we do not always have the capacity to look at all reported bugs in a timely manner. There have been many changes in Kubuntu since that time you reported the bug and your problem may have been fixed with some of the updates. It would help us a lot if you could test it on a currently supported Kubuntu version. If you test it and it is still an issue, kindly upload the updated logs by running only once:
apport-collect 1731767

and any other logs that are relevant for this particular issue.

[Launchpad Janitor (janitor)]

[Expired for Kubuntu PPA because there has been no activity for 60 days.]