I did backup version 2.5.0.12 (Dec. 2016)
Now, it seems installer versioning has been changed. The newest version for download is "2.0.119.430 CN update".
What are the differences, please? Thanks a lot!

I guess you're talking about D:OS EE and not the Classic version (D:OS). If so, this is what has changed;

CN Update (12 December 2017)
Added support for Chinese language

Update 2.0.119.430 A) (22 March 2017)
Added support for Cloud Saves in GOG Galaxy 1.2 and newer

Update (02 January 2017)
We have fixed an issue with the Mac version of Divinity: Original Sin - Enhanced Edition that prevented the language selection from working on Mac OS X Sierra systems.
If you continue to experience language selection issues on OS X Sierra after updating to the latest build of the game, please do not hesitate to send us a Support ticket.

EDIT - for clarity (I hope)

Thank you, that's helpful!

Another change that came with the December CN update is that it introduced a new bug that breaks the portion of the tool tips that say what level the skill is. I.e. where it should say "Novice" or "Adept" or "Master," it instead says nothing and the text is simply absent.

This bug makes the game extremely annoying to play.

I'm not sure if they ever fixed that bug since the patch was released. But if they didn't, then you're way better off reverting to the previous version of the game which does not have that bug in it.