InDesign Network Timeout Freezes ID
This really does belong on SU, but I'll tell you from experience that working across a network is not a great idea with InDesign. Copy to a local drive, edit, copy back is the safe workflow.
This is a situation that's existed with InDesign since the earliest versions. An InDesign file is in reality a highly complex database "under the hood." That's what gives it its power and flexibility, but it evidently makes it vulnerable to lost communication between the application and the file on disk. Unlike a network-based database, there is no component running on the server.
Remember, too, that ID is constantly updating a duplicate document (the recovery file) while you work. Check the preferences (Edit > Preferences > File Handling) and see where that file is being saved. If on the network, then it may help to set it to always save on the local hard drive, but for myself, I prefer to work local, store on the network.