Firefox has non-functional preferred language both after upgrade and clean install

[Timo Jyrinki]

It would seem something caused an incorrect language setting in Firefox, potentially due to 14.04 LTS -> 16.04 LTS upgrade.

Update August 2016: happens also on a clean Ubuntu 16.04.1 installation.
Update August 2017: also on clean 16.04.3.
Update August 2018: same on 18.04.1

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I noticed I'm getting redirected to English pages on help.ubuntu.com, even though that hasn't happened before like eg within the last month. I upgraded this machine to xenial today.

When looking at it more (after filing this bug originally against documentation) in Firefox settings -> Content -> Languages, I noticed the top-most item was "empty" (no language name) with [fi-fi] in brackets. Beneath it was suomi [fi] and english options. When I removed the "empty" language from the list, help.ubuntu.com started behaving correctly again.

At this point I don't have better information but leaving the bug open to be documented.

Original report:
All links at eg https://help.ubuntu.com/16.04/ubuntu-help/index.html.fi point unfortunately to English versions of the pages, like https://help.ubuntu.com/16.04/ubuntu-help/unity-introduction.html

The correct links would have the ".fi" added to the URL, like https://help.ubuntu.com/16.04/ubuntu-help/unity-introduction.html.fi

[Doug Smythies (dsmythies)]

??? It works fine for me. If I set my language to Finnish (.fi) in firefox, then go to the mentioned index page, then click to go to unity-introduction, I get the Finnish version of that page.

[Doug Smythies (dsmythies)]

I suspect, but am not sure, this is a duplicate of bug 1532537.

[Gunnar Hjalmarsson (gunnarhj)]

@Timo: You are not supposed to use URLs with the .fi extension directly, but you should change the preferred web contents language in the browser to Finnish.

Let's keep this discussion on the bug report which Doug mentioned; marking this as a duplicate.

[Timo Jyrinki (timo-jyrinki)]

Thanks for looking into it. De-duplicating and describing the actual bug which seems to be 14.04 LTS -> 16.04 LTS upgrade issue in Firefox.

[Timo Jyrinki (timo-jyrinki)]

Still happens in the default install of Ubuntu 16.04.1.

Removing the first entry in the language preferral settings (" [fi]") fixes the issue since the next line is the correct "suomi [fi]".

[Timo Jyrinki (timo-jyrinki)]

And still true with 16.04.3.

[Timo Jyrinki (timo-jyrinki)]

With the change that now the first (invalid) entry is " [fi-fi]". The second is the correct "suomi [fi]", so still it's that removing the first entry makes everything work as intended, but by default it falls back incorrectly to English.

[Timo Jyrinki (timo-jyrinki)]

This still happens on Ubuntu 18.04.1 LTS and latest Firefox. It breaks among else logging in to https://wiki.ubuntu-fi.org/ with a long Python backtrace ending up in language parsing error.