Ok i downloaded Skyrim, i cant run them both simultaneously - When i launch Enderal first then Skyrim, the 'broken' main menu of Skyrim just poping on, and if i launch Skyrim first then Enderal launcher doesent react on 'start enderal' button
You can't run Skyrim classic (or SE) and Enderal classic (or SE) in parallel. Even if they are separate games, you can only run one at a time.
So close Skyrim and start Enderal alone. There were rare problems in the past when Skyrim was not installed. That was the idea.
You can also try to start Enderal via skseloader.exe if that doesn't work.
Independently of that, we are not aware of such problems with the Polish version (you could of course test it by installing Enderal in another language like English, for example. But I don't think that's the reason).
So close Skyrim and start Enderal alone. There were rare problems in the past when Skyrim was not installed. That was the idea.
You can also try to start Enderal via skseloader.exe if that doesn't work.
Independently of that, we are not aware of such problems with the Polish version (you could of course test it by installing Enderal in another language like English, for example. But I don't think that's the reason).
So there is any idea what can be a reason why i cant run it? Im honestly run out of ideas 
EDIT: BRUH I RUN IT
I JUST UNCHECKED STEAM OVERLAY XD
EDIT: BRUH I RUN IT
I JUST UNCHECKED STEAM OVERLAY XD
Thank you for your solution 
. We will make a note of this on our "rare individual case" list 
. We will make a note of this on our "rare individual case" list Profile - Sledzward
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Profile - Kermit 61
"Meine Gefühle für Elfenwurzeln sind streng geheim, Späherin Harding!"
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Profile - Kermit 61
"Meine Gefühle für Elfenwurzeln sind streng geheim, Späherin Harding!"