Hi, we are sorry you are having problems with Adobe XD. In order to help you, you need to provide us with some information, such as the version of Adobe XD in use, the characteristics of your computer and whether this problem occurs only with a specific file or even with others.
We're sorry to hear you're facing trouble copy and pasting in XD. In addition to the details asked by Italo, we'd also like to confirm if you're able to copy and paste from the panels as shown in the screenshot below?
Or you're trying to copy and paste from Ctl+C and Ctrl+v using keyboard shortcuts? Or if, both of them are not working for you?
We'd suggest whenever it happens, try toggling the screens or press Esc key and switch your attention to some other things for a while and then let us know if that helps.