Language Pack Installation

Hi fellows!
I'm new to nopCom. I've just finished the installation of new version (2.30).
Knowing that nopCom is a multi-language platform, I assumed that I all to do in order to have the site running in other languages, was enabling it in the administration panel. I've noticed it's not that simple, because after I did so the site started to display a strange behavior every time I choose the newly-added language and going back to normal every time I choose English back.
After some searchs in the forum I realized I  had to download the additional Lang packs I need in my shop, which I did.
The question is, is there a specific method for applying this extension or all I have to do is transfer the pack to the plugins folder in the application folder?

Go to language details page (admin area). Click 'Import resources' button and upload a downloaded language pack

Thanks a lot my dear Andrei.

Hi,

I am unable to upload a Dutch language pack. I see only an older language pack is available. I see no changes in the header of old and new XML files, so I believe that does not matter.

However, I encounter next error when uploading zip-file which I downloaded from the website:

Data at the root level is invalid. Line 1, position 1.

From the source code I understand that the file should be plain xml and not in a zip-file. So unzip the language pack from the site before uploading it.

J.