copy paste command nor working after updating with High Sierra

flyaboutcouk wrote:

sorry did not work... pboard closes and reappears immediately....

That is normal. You actually want it to reappear.

The question is whether this fixed the problem (apparently, not).

Follow macjack's advice and test on a different user. It will probably work there.

Then run Etrecheck from your normal account and post its report here.

Open Activity Monitor and type "pboard" in the search field. Then choose pboard and in the upper left click on the X to force quit the process. Then try again.

Create a new user account or use Guest account, login and test copy/paste in that account.

Also, sometimes just restarting your Mac will get the copy/paste function working again.