Of course, instead of clicking Unpin you can also click Delete to immediately remove the entry.
Delete the contents of the temp folders (see How to delete temporary files in Windows).A new definition of the block might change the behavior in case the block definition is needed. When the issue appears when copying a block, the block might be corrupt.This can refresh the memory usage on the system. Memory fragmentation may have corrupted the clipboard.
Install object enablers for drawings created with applications such as Civil 3D.
This will also help reduce the overall file size and improve performance. Group objects together into blocks wherever appropriate. This will reduce the amount of system resources needed to move around within the drawing editor.
If there are many layers in a drawing, lock and/or freeze those which are not always necessary to have their content visible. Repair the drawing: After updating, repair the drawing using the following methods
Update to the latest video driver for the graphics card in the system (see How to update to the latest certified video driver).Install the latest updates for AutoCAD (see Install Updates, Add-ons, and Enhancements).
To reduce the amount of time that the drawing takes to process the 'COPY' and 'PASTE command, try one or more of the following suggestions below: Update software