AutoCAD: How can I solve a ‘copy to clipboard failed’ ?

what version of auto cad are you using? Are you trying to copy/clip into a new file? Or an existing file? If it is a new file just save as the old file (the one with the layers and stuff in it) as the new file. Also try cutting instead of copying sometimes that works. and then there is always the import file

Try to Recreate the drawing file. Got this from the official AutoCAD website:

1. Create a new file from a standard DWT.
2. Use the INSERT command to import the damaged drawing.
3. Explode the resulting block.
4. Enter LAYOUT and then choose Template.
5. Select the original drawing file and click Open.
6. Import the necessary layouts.
7. Use WBLOCK to extract the drawing to a new file.