Issue:

When opening a drawing in AutoCAD, the following message appears:

References - Not Found Files

One or more referenced files could not be located or read. What do you want to do?
 
References - Not found files
Once the drawing is opened, some or all the referenced files are not loaded. The following types of references may be affected:
  • Drawing files (DWG).
  • Raster images (JPEG, JPG, BMP, etc.).
  • PDF underlays.
  • DWF files.

Causes:

  • The xref is nested and the parent file has changed.
  • The drive letter where the xrefs are stored has changed.
  • The actual xref file was deleted or moved.
  • The xref file is corrupted.
  • Lack of permissions to the folder or server where the reference files are located.
  • A circular reference is present.
  • The referenced file has been renamed.
  • Third-party applications (e.g. Advanced System Care), turning off DNS client, IP helper, and net logon when run.

Solution:

Try one or more of the following solutions:

Update AutoCAD

Install the latest updates for AutoCAD (see Install Updates, Add-ons, and Enhancements).

Troubleshoot the file location

  • If several referenced files stored on a server or locally cannot be read, change the paths for multiple xrefs at the same time using the Reference Manager tool (see How to change paths for multiple XREFs [video]).
  • Make sure the folder containing the drawings is unzipped.
  • Move or copy the xref files into the same directory as the DWG which is calling them.
  • Change permissions to provide full read/write access to the location of the referenced files.
  • If the files are stored on different servers, move them to the same server.
  • Any xref that shows "Unreferenced" can be detached from the drawing.

Troubleshoot nested Xrefs

  1. Enter XREF at the command line and click on the button within the External Reference palette to show the Tree View, or press F4 while the palette is active.
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  1. While in the tree view, the unresolved nested xref can be clearly identified with the parent xref. 
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  1. Open the parent xref identified in step 2. 
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  1. On that file, resolve the nested xref by browsing to the file location.
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  1. Close and save the parent xref.
  2. Check if the xref is now resolved in the master drawing.

Check the external reference saved path

In the Details section of the External Reference palette, select the unresolved xref and look at the 'Saved Path' entry. Make sure that the path listed here is where the file actually is stored. Particularly, look at the drive letter that is mapped and make sure the files are located there.
 
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If the Saved path is incorrect:
  1. Right-click the name of the reference.
  2. Choose Select new path.
  3. Navigate to the correct path and select the drawing.
Notes:
  • If an external device is connected, it is possible that it temporarily took over the mapped drive letter.
  • Same network drive is mapped to different drive letters for different Windows users/workstations.
  • According to the specified workflow, it might be needed to set the reference to use either an Absolute or a Relative path. See: About Setting Paths to Referenced Drawings .

Use the ProjectName tool

  1. On the command line in AutoCAD, type OPTIONS.
  2. In the Files tab, select the Project files search path entry.
  3. Add a new folder (use the job number or job name, for example).
  4. Add the path(s), directed to wherever the xrefs that make up the drawing(s) are located.
  5. Open each of the troublesome drawings and run the PROJECTNAME command.
  6. A prompt for a new value will be shown. Use the exact same name used in Step 3.
  7. Close and reopen the drawings.

Troubleshoot the files

Enable demand loading of xrefs

  1. On the command line in AutoCAD, type OPTIONS and then click the Open and Save tab.
  2. In the External References section, from the Demand load xrefs drop-down list, choose Enabled.
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Turn on connectivity services

  1. Within Windows, go to Control Panel > Administrative Tools.
  2. Click on Services and check if DNS Client, IP Helper, and Netlogon are running. If not, start them.

Detach the referenced files

If it is not needed to resolve the missing referenced file, right-click it and select Detach to prevent the dialog from being displayed.

Embed missing images

For raster files, an alternative is to embed them as opposed to referencing (see  About Object Linking and Embedding (OLE)).