Nobody can know anything without further information. there is a million reasons why objects can rasterize like a simple DPI settings mismatch or specific appearances being applied in AI.
Thank you for your reply but what details do you need?
I have a problem with copy paste from illustrator to photoshop. The pasted picture/element is rasterized and not sharp. I have this problem with vector element too.
I'm using Photoshop CC and Illustrator CC with Mac OS X 10.7.5
I've installed the CC update of these programs.
It worked for several months until last week.
in the picture you can see two icons who have been copied from the same Illustrator file and pasted in the same Ps file a few days apart.
The smiley icon is clean and the trash icon isn't...
I contacted Adobe support. I reset Photoshop preferences and the bug is now fixed.