Can't select language packet in Preferences

[ChrSchultz]

Describe the bug
I am not able to select other language packs for ui.

To Reproduce
Steps to reproduce the behavior:

1. Go to prefernces
2. Click on '.language 'en'
3. try to select cn or de or each other...
4. remark, you are not able to select any other language , but en.
5. than I have a look into the installation Directory in laguage and all other languages are installed.

Expected behavior
I expect, selecting many other languages

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Window 10 21H2 -64bit
• Version: 2.0.0 rc3

Additional context
I tried in localuser and system installations mode and both is the behaviour the same

[per1234]

Hi @ChrSchultz it is possible to install the stock "language pack" extensions by following the instructions here.

However, that only provides the base UI translations. None of the Arduino IDE-specific translations are in those extensions.
My understanding is that the integration of the Arduino translations depends on #712

[qizaizi]

The plugin directory is in the installation location arduino2.0\Arduino IDE\resources\app\plugins