Some special characters and accents do not display correctly

[kartoffelsalat]

The german umlauts (don't know if this is the correct english, leo.dict.org told me so, i mean these: ä, ö, ü, ß) are shown as "?" in most of the cases. I attach a screenshot of the update-manager, where you can see the button "Pr?fen". It should be "Prüfen".
Sometimes (or better in some applications, but I don't know which. Firefox e.g. is showing them normal) the umlauts are shown correct, most of the times not.

[JC Hulce (soaringsky)]

This depends on the translation within the application itself. I speak a bit of German, so I know what you're talking about. If you have time, you can actually find the project within launchpad and help translate it very easily.

However, this isn't an issue specifically withing UGR, so I'm labeling it as wontfix.

[JC Hulce (soaringsky)]

Upstream translations issue

[JC Hulce (soaringsky)]

I looked at the translations, and everything was there. It turns out that the Cantarell font, which is the default in GNOME 3 for most things, only supports English. If you would like to change this, it is possible with the 'tweak advanced settings' tool.

[Daniel Sandman (almehdi-deactivatedaccount)]

It works perfect with Swedish which use å, ä, ö so i am not sure that is a correct assumption.

[Georg Duffner (mcduff)]

The Cantarell font does contain all the umlauted letters and germandbls. In fact it covers (almost) every living european language from icelandic to turkish.

The OPs problem sounds more like an encoding problem.

[kartoffelsalat (silberzwiebel)]

I switched the font to Ubuntu, but the problem still exists. I can find "?" in the update-manager, software-sources config, Ubuntu Software Center and Ubuntu One, but until now in no other application (I will report if I find them). So maybe it's a problem with the Ubuntu-specific applications? Ah, not all the umlauts are shown wrong in these applications, some are ok, but most are wrong.

[kartoffelsalat (silberzwiebel)]

I saw another "?" in Gnome-Do. If you search with Gnome-Do for ? you see a lot of them at the wrong places.
In the Gnome Shell Activities > Applications these items are spelled correct.

[JC Hulce (soaringsky)]

Ok, so maybe this isn't a font issue, but an encoding one.

[JC Hulce (soaringsky)]

Found the upstream bug and linked it