There is a small bug (SPR CMAS88WGWQ) in the Lotus Domino pubnames.ntf template. If you update your directory (to 8.5.2) or use the 8.5.2 pubnames.ntf template to create a new application from it, you can no longer copy and past (or cut and past) elements in that application. If you see similar issues on your side, there is a fix and a workaround available.
If you need a workarround, here is my one:
1.) open the design properties from the application.
2.) go to the design tab.
3.) remove the "inherit design from master template" option (clear the field).
4.) Open the application where you have the issue with.
5.) go to the agents (code -> agents).
6.) delete the agent called " RenamePastedAccounts"
This is a WORKAROUND, if you get a fix from IBM you need to revert that changes! This can be done when you put back the "inherit design from master template" and run a design refresh.