By Dennis Collin
The image above is a frequent question on our support helpdesk and on our training courses. When working in a project or if you are in receipt of some AutoCAD drawings from a third party a dialogue box will appear if some externally referenced files have been specified but cannot be located or read. This can be due to several causes depending on circumstances.
Either the file has not been supplied with the transmittal or perhaps the file is corrupted and cannot be read by AutoCAD. It could also be a path change or the case of a drive letter being remapped to a different letter, or a change in folder access permissions. It is advisable to check the external references list to see which files are missing, or cannot be found. This can prove useful when talking to the originator of the drawings.
If it is the case that the file hasn’t been included contact the sender of the files and ask either to include the reference files with the transmission. The best way to ensure all relevant files have been sent is to use the Etransmit command to package all the required files into a compressed zip file or folder. Alternatively, referenced DWG files could be bound into their main drawing, embedded rather than linked. Unfortunately, other formats like raster images cannot be bound into drawings and must remain linked. Therefore, the Etransmit command for the delivery of large number of drawings is a popular approach as it bundles all necessary files for viewing, editing and printing.
If the file can be located via browsing folders on AutoCAD, it is possible the file has been corrupted. A useful command to resolve this is the Recover command, if this file in turn has reference files attached which also has problems then the Recover with Xrefs is a fast way to resolve multiple issues.
In the event of files, folders, and drives being renamed or moved, AutoCAD comes with a very useful external utility called Reference Manager. Located in the AutoCAD program group the Reference Manager will allow the selection of multiple drawings and folders and scan those drawings for any links. Where links are valid the application displays a green tick. For files that need to be re-pathed, a yellow warning will be display the Reference Manager will allow these path links to be set to the correct folder and drive without having to go into AutoCAD. It also allows the changing of path type from explicit full path including drive letter to a relative path type for increased flexibility.
The Reference Manager is a useful utility for anyone needing to manage a project. Simply add drawings, issues are automatically listed, and problem items can be selected, and file paths adjusted and corrected.
External Reference Files, the Etransmit function and Reference Manager are all discussed and demonstrated in full on our AutoCAD Intermediate training course or in a more bespoke workshop. For more information visit https://training.cadline.co.uk/ or talk to a member of the training team on 01784 419922.