If your device's IMEI number becomes nulled or corrupt for some reason, you might experience network connectivity issues. Open your device's dialer and type *#06#. If you don't get the IMEI number, which is a 15-digit number, but you get Null instead, there is something wrong with the IMEI.
If you are not sure how to fix this issue, I suggest you to ask a friend, or take your device to a repair store. Also, I advise you to check this useful article which shows the users how to resolve the IMEI issue, on Technobezz.
Note: See the don't know how to find my device's model number guide if you can't read the IMEI and you followed the above-mentioned instructions.
If you have a Blackberry device and you experience issues which you can't resolve by yourself, contact their technical-support team, which will help you resolve them as soon as possible.
Contact them on: 1-877-255-2377 from 8 a.m. – 11 p.m. EST
Note: If you live in a country other than the USA, contact Blackberry's authorised store in your country.
You need to update your mobile device in a timely manner, as the contains bug fixes, out of which one might be the network issue. Usually, mobile devices inform you when update is available, automatically, but sometimes you need to check for updates (and install them) manually.
See the don't know how to update my operating system guide to learn how to check for and install updates manually.
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.