As usual and in a certain logical sense, new bugs appear in iOS that allow access to the system without knowing the lock code or directly blocking it completely by having to restart the terminal to solve it.
Well, according to the latest reports, it has been discovered a bug in iOS 10.2.1 that completely blocks the messages application, but fortunately, there is a fairly simple solution to the problem.
As for the bug itself, simply send someone a contact through the Messages application, so that later, when the victim runs Messages and try to open the contact, see how the application has been completely blocked.
In this way, the victim may not rerunning the Messages application, and, if you're thinking, restart the device does not work at all, since the application will be blank and will not operate properly.
Fortunately, and as I said above, solving the problem is as simple as accessing a link that automatically sends a message to the Messages application to restore it , allowing re-run as normal as if nothing had happened.
Otherwise, and if you want to try it for yourself, for the contact can download it from here , but yes, remember who to send it to another person it is necessary to upload it to a storage service in the cloud how iCloud Drive or Dropbox .