How to fix this it wont let me install skse this is first time something like this happend ?

[NIghtWolf2400]

Vortex nnds to access c:\games\Steam\steamapps\common\Skyrim Special Edition but doesnt have premission to .If your account has admin rights Vortex can try to unlock file for you .

[Pickysaurus]

Did you run either the game or Steam as admin? If so you may have locked Vortex out of being able to modify the game.

 

You can also try fixing the permissions on the folder itself.