Possibly, but let's try some more troubleshooting first so we're not just stabbing in the dark.
- Do you have any clipboard managers running?
- What content are you trying to copy?
- What application does the content come from?
- Do copy actions work on text that you select in something like Notes.app?
- Have you taken a look at any logs to try and narrow things down?
Edit: Woops, I've just gone to the next tab I opened and seen that there might indeed be an issue with KM 9. See this thread - Workaround to Clipboard