The IDLK file extension is used by Adobe InDesign's DTP (Desktop Publishing) solution for so-called lock or lock files. With InDesign, for example, you can create print templates and layouts for print products such as flyers, catalogs or brochures.
An IDLK file is automatically generated by the InDesign system when an InDesign document (extension indd) is to be managed. The ability to manage files is part of workflow management for InDesign and InCopy shared files.
An IDLK file ensures that only one person can ever work on a document. An IDLK contains the name of the associated indd file and is usually deleted after InDesign completes. Remaining IDLK files can be deleted.
Most often resolving problems with opening IDLK files is very simple. Just install an appropriate program that supports such files. All of the listed programs support IDLK files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of IDLK files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate IDLK files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Adobe InDesign applications is not on the list, select "Browse" option in order to manually locate the directory where Adobe InDesign has been installed.
Sometimes problems with opening IDLK files may not lie with the application itself, but can arise due to other causes, such as: