INFO: Roaming problems - no network service - manual network selection required
My wife and I recently went to Spain for a few days. Roaming was enabled for both of our phones.
For the first couple of days, our phones worked fine, but then both lost all service (nothing showing on signal strength, "emergency calls only"). This persisted for over 24 hours despite repeated phone reboots and despite being in areas where we had had good signal strength previously.
In desperation, I tried the manual network selection. The phone listed half a dozen networks, all showing as "unavailable". I chose one and the phone popped up a message that it could not be used, but I could try and connect anyway. I did try, and it did work - full service restored. I put the network selection back to automatic and after that, I had no more problems.
I've posted this in case it may help anyone else who finds themselves in the same situation.