Sharing files on hostednetwork 0x80004005 error

I have two devices, one running windows 7 embedded and a tablet running Windows 8.1

The Win7 device is running a wlan "hostednetwork", and also sharing a folder, which the Windows 8.1 tablet needs to connect to.

I have a batch file that starts the hostednetwork on startup on the Win7, and the Win81 tablet is set to "Connect Automatically" to it.

However, if both machines are restarted, then it seems that when the user tries to connect from tablet to the shared folder, they get an error 0x80004005 ("Unspecified error").

Now here's the thing. I can access the tablet on TeamViewer, but only if they disconnect it from the hostednetwork and instead connect to their local Wifi router where they have Internet access.

The Win7 machine is also visible on this network. So when I log into the tablet using TeamViewer, I can actually connect to this shared folder without a problem.

Then if I ask the user to switch it back to the hostednetwork, they can still see the shared folder. But then they restart both devices and once again get the 0x80004005 error. They have verified that the tablet is indeed connected to the hostednetwork.

I have searched for the cause of this error, but haven't been able to find anything on this intermittent connection.

Also, I have the same setup here at my desk, and it all works fine - even after the restart. Unfortunately this user is in another country so I can't check it for myself, and since the tablet can't have both Internet connectivity and a connection to the hostednetwork at the same time, I can't even use TeamViewer to replicate the issue on their device.

Though it may be worth pointing out that that user has internet connectivity on the Win7 machine as well as using a WiFi device to run the hostednetwork. I think they even have a second WiFi device but I'm not sure what that's being used for.