Copy to Clipboard Failed

The "Copy to Clipboard Failed" error message is usually caused by proxy entities in the drawing. Proxy entities are custom objects that are only readable with specific applications. A common example of a proxy object is a Surface entity (created by AutoCAD Civil 3D). This type of object is not usable with standard AutoCAD or IntelliCAD. Proxy objects are not easily selected, and are therefore not easily removed from the drawing. However, there are ways to convert or remove these objects.

Option 1

Because of the prevalence of proxy entities created by AutoCAD Civil 3D, a quick-and-easy attempt to convert these entities to use the File Pulldown Menu > Import > Civil 3D > All Civil 3D Objects. Note that if the proxy entities were not created by Civil 3D, this will not resolve the issue. Unfortunately, unless you know the origin of the problematic drawing, you likely will not know if the proxies are from Civil 3D or not.

Option 2

Alternatively, you can try inserting the problematic drawing into a new, empty drawing with the below steps. Please note that these steps may not work for all scenarios.

1. Open a new drawing
2. Run the CLASSICINSERT command
3. Select the problematic drawing and configure the dialog as shown below
   
4. Click OK

Option 3

Another, often effective option is to use the free Zombie Killer app from the AutoDESK App Store. This app will remove proxy entities from the drawing and will re-enable copying objects to the clipboard. After installing the app, open the problematic drawing and run the KILLZOMBIES command to remove proxy entities.

Additional information about this error is available in this AutoDESK support article.