Recent versions of Firefox introduced multiprocess support. The entry Multiprocess Windows in about:support indicates the state of multiprocess support. In my case, it appears as 0/1 (Disabled by add-ons).
I disabled all my extensions and re-enabled them one by one to find the culprit(s). To my surprise, the extension causing the problem is Ubuntu Modifications. I disabled it, restarted Firefox, and the state of multiprocess support became 1/1 (Enabled by default).
The extension doesn't apear to do anything major.
- Any idea when this will be fixed?
- Would disabling the extension break anything?
Update: The issue doesn't appear as fixed in Launchad, but in practice it is no longer causing problems and multiprocessing is now working with Ubuntu Modifications enabled.
2017-05-13 update - Currently no resolution for ubufox plugin, and no ETA. Workaround is to disable/remove ubufox plugin. Master tracking bug on Launchpad: https://bugs.launchpad.net/ubufox/+bug/1627808. If impacted, make sure to click on the "affects me" link at the top of it.
