When i login to my pc desktop effects are disabled by default. I have to pres Shift+Alt+F12 to start them.
I am pretty sure i may have messed up some setting. Can someone help me?

Ok i fixed it.
For anybody looking for the solution, i found the solution on https://askubuntu.com/questions/758250/how-to-deactivate-all-the-desktop-effects-of-kde-permanently#758266
Basically you head to System Settings > Hardware > Display and Monitor > Compositor and enable the Enable compositor on startup option.