Some functions got disabled and i don't how to re enable them

1) the image is not a link to an image, say a .jpg or .png file
2) try being a bit more descriptive of your problem
3) try systemsettings -> workspace behavior -> screen edges

When i select an edge to add a command i've only some option enabled the others are disabled (like "present windows")

you probably disabled the effects required to allow those options

systemsetting -> desktop effects -> all effects ->
-> enable present windows
-> enable flip switch
-> apply

The "Enable desktop effects at startup" was desabled, thank you very much