Zte Grand X In User Manual page 322

PIN Code
blocked
Unable to
enter
information
into the
phone book
You have entered an
incorrect PIN code three
consecutive times.
The phone book's
memory is already full.
Contact your service
provider. If the service
provider provides the
(U)SIM card's PUK
code, use the PUK code
to unlock the (U)SIM
card.
Delete unnecessary
data from the contacts.
322