I had been getting "Error code 16, switch 390" error, had my carrier take a look at it, then they gave me some instructions to refresh the PRL, Profile etc.
Here is the process I followed:
I fired up the dialer, used ##72786#, but it didn't ask for the MSL, I think the MSL was one of the pieces that was erased. Anyway, it asked if I wanted to set things to factory default, I say okay, and it reboots.
I initiated a PRL Update, that succeeded, but no reboot. I rebooted manually.
This time when it comes up it starts the "Handsfree Activation" process, this "activates" the phone, it immediately does another PRL update (on it's own), this time it reboots on it's own.
It comes up again, and looks for a firmware update, says I am up to date.
I try *99 - "the feature code you have entered is not valid" - Better than it used to be!
I try making a phone call - IT WORKS!
I try an SMS - IT WORKS!
Now I try running a Profile Update - "Update is complete", no automated reboot this time.
Doing a manual reboot - 4G works, 3G does not, and I'm not sure how to test 1x.
I'm pretty sure the remaining pieces are those data passwords that, apparently, we can't get.
I contacted Sprint, but of course they say I need to work with my MVNO service provider, even though I'm on their network.
But my MVNO RingPlus is not being super helpful, saying the only reason to get those passwords if if the phone were flashed or something, and they can't support me in those cases. Which, true it is rooted, but that is not the cause of this problem, as I have seen multiple posts about this happening to people with stock phones.
My next recourse would be to "Swap" service to a different device, then back to mine as apparently those data passwords would be regenerated. But I don't have any extra Sprint phones. If anyone has an MEID they wouldn't mind letting me "borrow" for a little bit I would be grateful.