COPY and PASTE
If you have installed Service Pack 1 for AutoCAD and AutoCAD LT 2014, try the following procedure if previous methods fail:
1. Open the DWG file.
2. With the LAYER command, assure that all layers are on, thawed, and unlocked.
3. Copy all objects in the drawing to the clipboard (CTRL+A then CTRL+C).
4. Open a new file and paste all copied objects (CTRL+V).
5. Save the file.