I am wondering if anyone else is seeing this issue and/or if someone knows how to fix it.
We have a network drives that our users save their files. Our InDesign files are shared between two team members when they are being completed. One of our team members had an InDesign file open and another team member was able to open the same file and edit it even though it was already opened by the other user. This has happened about 3-4 times for our team members. The original team member is getting the message "Unable to save because file is already in use".
It sounds like there is an issue with the Indesign "lock file" that is created when you open a file (on a server or local drive). Not sure what kind of server you are using. If you have an IT dept that manages the servers you can have them look into it. Otherwise, you'll need to improve communication between team members: "I'm working on XX right now" etc.