Phone locked! I know my 4-digit pin, but my phone doesn't recognise it.

[scottishagate]

Sony Z1 Compact running Lollipop. I've had this 4-digit pin for a year, working with no problems. But suddenly today, my phone is locked and does not respond to my pin. Also, there is no "incorrect pin" message after 4 digits, I can enter multiple digits without any error message.
Grateful for your insight and advice.

 

[B. Diddy]

Welcome to Android Central! Is it the exact same PIN entry screen that you're used to, or does it look different?

 

[forgetmeknottihs]

I had sort of the same issue but it wasn't the 4 digit pin, it was an. Eight digit pin that that it wanted. It was to unlock the Simms card. The error message was PUK-locked SIM card. You have to call your service provider to get it - unless you have the original box that your SIM card came in - the 8 digit pin can be found on that box. I have to say, it was absolutely NOT. A good experience with Verizon trying to connect with them through Facebook. When I couldn't call I had to use FB