"To fully localize the application you can download the Shadow4.r2skin-addon (...)"

OK, but what should I do after download? Where should I unzip it? To "Locale" or "Skins" folder? Or maybe I SHOULDN'T unzip???

What should I do with file "language.xml.diff"???

I've tried to copy "polish" files separated from the others, zipped, unzipped, and i can't install my language bitmaps succesfully. R2 still doesn't see them, or even totally crashes when I replace a few files. Can somebode describe the process of installing language bitmaps step by step, like for idiot (file A to folder B, Files C and D to folder E, in file X change text... to... )?

No, you shouldn't unzip it. Just double click the file and it should be installed automatically. If that doesn't work, drop it over one of the Rainlendar's windows.

I've done it in both ways several times, and the report was "skin succesfully installed". But after "installation" I still can't change SkinLanguage option in Advanced - it's still only Default or English (after restart - before it, of course, too).

Check that the Shadow4.r2skin contains all the languages.

- Rename it to Shadow4.zip
- Open it and check that the images are there (Events-bg-Finnish.png, Events-bg-German.png, ...).
- Check also that languages.xml contains the list of languages.

I've checked. It seems to be ok (but I don't know if there isn't any goofs). It doesn't work anyway.

Does anybody have similar problem with any of other non-english languages?

I have the same problem, I can not change the interface language into (for me) Dutch. It stays in English.
I have done wat you said:

Rename it to Shadow4.zip

.Open it and check that the images are there (Events-bg-Finnish.png, Events-bg-German.png, ...).
They are not there, only English.

.Check also that languages.xml contains the list of languages.
Does not contain the list of lanquages.

How can I change this, so that the interface also changes the lanquage.

Already thanks.