Please tell us what you are trying to copy from?
What is happening step by step? Is no color picked up? Or do you just see a different color?
1) I select the object i want to change
2) Select eye dropper
3) click on another object who's fill i want to copy
4) Nothing happens.
*if i do it with type it randomly picks colors if nothing at all.
The other object is a vector object and it is not grouped (this might be an issue with version CC2018)?
If you want to copy from inside a group, press Shift while clicking
check the eye dropper settings: double click the tool if it is set up to copy /paste anything
sometimes applications might just get stuck, try a restart (of the computer)
Yes i figured out the grouping issue a while ago. you cant select from groups. Why is that a problem?