I'm having difficulty copying and pasting between drawings. This does not happen all the time and there's no consistent variable I can go by to figure out this problem. I've run recover and audit to check for corruption, but nothing is found during either process.
Do you have any suggestions?
Thank you very much for your time.
The most common reason I have encountered for copy/paste issues is metadata.
Metadata is information attached to AutoCAD entities, such as Civil 3D information. I have found that AutoCAD will display the entities (since it is an AutoCAD entity), but will not copy/paste with the metadata attached.
A way to test is to export the DWG file to a R12 DXF, and re-open. The DXF export will remove the metadata from the entities.
Give it a try and let me know if this worked for you.