The coredraw output dxf format CAD cannot be opened, and it prompts "The input is invalid or incomplete---the drawing is abandoned". The specific operations are as follows:

1. When encountering "DXF input When the error message "Invalid or incomplete graphics was abandoned" is displayed, we can use relevant CAD editing tools to achieve this. First, search on Baidu to obtain relevant CAD editor tools.

2. Install and run any CAD editor tool, and click the "New" button to create a new DXF document.

3. Next, switch to the "Editor" tab and click the "Merge" button in the "Drawing" list. The "Merge Files" window will open.

4. After the "Merge Files" window opens, click the "Browse" button to the right of "Name".

5. Then select the drawing file that cannot be opened directly.

6. Next, you can directly click the "Select Point" button to select the location of the newly inserted graphic. Click the "OK" button to complete the insertion operation of the graphic.

7. If the graphics cannot be seen directly after inserting it, we can switch to the "Viewer" tab and click the "Fit to Window" button in the "Position" list.

8. Then we can see the inserted graphic content.