000513: Unable to open <value>.

Description

The CAD file is not accessible to the Import From CAD tool. The CAD file may be in an unusable format or is not in the specified input location.

Solution

Ensure that the file is in the location specified. Another possible solution is to preview the CAD file in ArcGIS using ArcCatalog. If it is not viewable, resave it in the CAD host where it was created.