I am experiencing this same issue. I have been fighting it for about 3 months now. I made a post here yesterday that outlines all of my troubleshooting.
The share that the users worked off of used to be on a linux box and we moved that over to a server 2012 box to see if that would fix it and it didn't.
Have you had any progress troubleshooting this?
Yup - a pretty archaic one but (touch wood) it seems to work. Or at least has so far this afternoon.
Open up command prompt (win-r / cmd) and input:
ping -t [server ip address without the square brackets]
This sends a tiny packet to the server every second and keeps the connection from dropping.
As I say, it's not the most elegant but seems to work. You'd think, with something so simple, Adobe would be able to add such functionality into InDesign. It's not like it's producing a huge amount of network traffic to constantly ping the server, and presumably they could dial down the frequency a bit - just sufficient to prevent the connection from dropping out.
I think I may have solved the issue we were having. The drive the indesign files are being stored on is being mapped by a GPO. It is using GP preferences to map the drive and it was set to "replace". Since group policy refreshes at different intervals throughout the day, it will disconnect the drive and connect it once it refreshes. InDesign doesn't like this and will error out. If you set the action in the GPO to "update" or "create" it won't disconnect the drive.
After I made the changes we haven't had a crash.
Windows 8 and 8.1 must apply the same GPOs differently. Check this article out.
I will do more testing but I think this is what is causing my problem,
Hope this helps!
Nice - yeah we use group policies to map them... we'll give it a go!