It looks like the drawing has lost the link to the model. The file may have been moved, or the name changed. Close the drawing, then go to File > Open. Browse to the folder containing the drawing and highlight it but don't open it. Click on the References button at bottom to browse to the files current name and location.
Michael,
It looks like the drawing has lost the link to the model. The file may have been moved, or the name changed. Close the drawing, then go to File > Open. Browse to the folder containing the drawing and highlight it but don't open it. Click on the References button at bottom to browse to the files current name and location.