Hi CraftyCockney
Welcome to the eForum and I’m sure we can help you,
The lock sign on your screen would indicate e the current status of your handset, ie. that it is locked and asking for a password etc. The solution is to include at least one letter and one numeral in your password (as stated by the error message:)), so instead of simply having, say, Vodafone as a password, you'd need it to be Vodafone1 or Voda2fone etc, at least a numeral included.
Please try this and give us an update as to whether you've made progress, once you've succeeded you'll need to make sure your registered for
My Account services, this ensures that if you ever lock your sim pin you can easily 'self service' your way to an unlock code, as well as access to 40% of all account query issues,
Always here to help.
Reidar
eForum Team