Sprint: your account can not be validated [Solved]

I got this recorded message when I swapped my cell phone from Samsung Victory to Galaxy S3 and tried to call somebody.

The S3 used to belong to my son, but he upgraded it to HTC One. which left the S3 unused. The phone is more capable than Samsung Victory that I was using, so I decided to swap the phone.
The process couldn’t be easier. After hard resetting and wiping my son’s setup including gazillion of text chat history, It can be done online by logging into sprint.com and select “upgrade my phone” menu selection from my device page. Sprint.com site is clever enough to recognize that I have unused Galaxy S3 under my account and suggested the device as a target device for the swap. It was just the matter of following the step by step instructions on the site page.

So the swapping was done in no time without pain, or so that I thought.

After the swap process, the phone was recognizing network. Setting up Outlook mail service, Google service and Dropbox service was completed without any issue. All I needed to know were the user name and password. Then the phone was receiving e-mails.

I could not call from the phone however. When I tried to call the phone from the land line and got the voice mail message. Also, when I tried to turn on the hotspot, I was told I was not subscribed to the service (which I am)

I first try to call Sprint but I was on hold for 20 minutes. during that time I was googling the net and found several posts regarding this problem. Most of the responses, including the ones from sprint support team was not helpful at all. Then I stumbled accross this one. This one turned out to be the right answer.

The process to remedy this problem, turned out to be simple. you need to go to “Settings” -> “More” ->”System Update” then select “Update Profile”.
The phone will want to reset itself once the update is complete, and after the reset, everything started to work.
I suspect, there was still some of my son’s profile data remained on S3 and it confused the network connection.
Now I have a cell phone with bigger size screen and bigger size memory. Considering the fact that my wife carries S4 and my son HTC one M8, I am lagging in the technology but hey, I am perfectly happy with what I got for free.