A specific DWG drawing file does not neccessarily carry all the information required to display end further edit the drawing contents. The drawing often depends also on a number of other, external files - the typical example are xrefs, but it may be also images, underlays, plot configurations, data links.
Another problem may be in the relatively referenced external files - on a different computer, they may resolve to a wrong referenced file (in another path).
That's why it is important to have all information about external references from the given DWG drawing. The free utility CADstudio Depends displays a list of references including full paths which they are currently loaded from - i.e. where they were found (resolved) in the current AutoCAD session. The add-on application Depends can display either the individual types of external links separately, or all links (references) at once. You can choose (see the option Settings) between the short name or the full path of the external files.
A separate option unResolved can list xrefs which were not found.
Besides displaying the results, the application also fills the LISP variables _DEPENDLIST (a list) and _DEPENDSTRING (a string), which you can use for processing the results in your own macros, or for copying the result text:
or for inserting the overview of external references as a text into your drawing - you can use this variable in a text field (see FIELD > Lisp variable > _dependstring).
A sample output from the DEPENDS utility:
List dependencies of type
[Xref/Image/Font/Plotconfig/Datalink/Underlay/unResolved/Settings/All] < All>: All
You can download the DEPENDS utility from www.cadstudio.cz/download, load it using APPLOAD and run it with the Depends command.