Firstable, I'd like to say hello and introduce myself as new member of this community. Turns out I have an Xperia P with Android 4.1.2 and i've been using the lock pattern feature for a while... Today I wanted to disable it but it seems like I can't do that, the "None" option is disabled and I can't disable it. Do you know why does this happen? (See attached screenshot)
I'll be waiting for your answers.