I tried it but it crash

When I shall change any traits like Attack speed or param meters as regeneration the editor freezes and sometimes it works and sometimes it completely crashes. Anyone else have this problem?

There is a problem if your OS is set up to something other than English (where you use , for thousands, for example).  I haven't read through it thoroughly, but this causes issues.  If you do a bit of a search (try the pinned Bugs thread first) there IS a solution that requires you to make a small change to something in your OS.  That will at least keep you going while the bug is being fixed, and then once it is, you can revert your OS changes.

Here's what you can try to help yourself,

I'm not on an english Version of Windows so please try to figure out what I mean:

In Windows, go to your System Settings -> Region & Language -> More Settings button (lower right corner) ->

right in the first tab, in the first textbox (named something like "decimal seperator") replace > ,  < with  > . <

(insert a simple "dot" where the comma or else was)