BBM Unable to Chat or Connect to BBM Server

A friend experienced this problem; he woke up one day and discovered that his BBM (BlackBerry Messenger) will no longer communicate despite of the fact that  he is still on active BIS. So what was the problem? troubleshooting such device is somewhat confusing to some Blackberry users because the Blackberry will still browse the internet that means the problem is not from the ISP (Internet Service provider), let just keep that aside, BBM server is where the fault is coming from, perhaps conjunction in service or any other reasons beyound my scop let's just try and fix the bug. He was probably locked out of BBM service for a while (perhaps to teach him some lessons).

Finally get it fixed by, what they called, Hard Reset
in case you don't know much about the so called hard reset and how to execute it. You can check this page http://www.brilainfo.com/2014/03/how-to-reset-blackberry-smartphone.html