What are you copying?
From which application?
Where do you paste it?
Hi Willi, thanks for answering,
basicallyi have ID 5.5
OS Yosemite 10.10.5
when i copy anything, a graphic, text box, circle... from indesign (even from the same page and paste also on same page) and its not a matter of keyboard stuck cause everything works on all other softwares including indesign CC
i will try to re-install unless you think its the preference file
InDesign CS5.x is not supported with Yosemite or later. It might work, but if such problems come up you might have no solution.