Copy & Paste Fail

LayOut fails to copy and paste window from another sheet. All I get is “Failed to retrieve data from clipboard. Try copying the item’s again”
Any ideas what is causing this.

More info would be useful to narrow down what could be causing this.
The last time a copy&paste problem was reported was with a Windows 8(.1) system. What operating system version do you have and what LayOut version? [if on Win] Is .Net framework installed?

By window, do you mean a model of a window or an application window?

How do you copy&paste, with short cut, context menu or Edit menu, and is there a dofference?