I too have been having this issue almost daily. It even popped up and interrupted me while I was in an app, closing the app.
Anyone in the know??
I have been getting the same error message for about a month. The only thing the troubleshooter does is tell you to remove, reinsert and restart phone. I've done this twice, to no avail.
Same Problem. I remove my case, find my key to open the sim card tray, take out the sim card, put it back in, and close it. Then, I have to put the case back on. This is a pain in the [removal required by the Verizon Wireless Terms of Service] It has happened about 5 times now, and if you don't have the key with you, you are [removed] ....and if you are out of town on business and lost without your phone, tough!
I had the same problem a few months ago...random, like 3 times over a month...I had one Verizon tech state that if the phone loses it's signal it will automatically roam....but can't switch back.....IDK, I have a network extender....she said that happens go to settings - mobile networks...and make sure LTE/CMDA is selected....it hasn't happened since...so let me know if this helps