Sim card error message

[SamsungFan01]

Hi I was wondering if anyone can help me. I have noticed my Samsung Galaxy S3 is popping up a Sim card error message. This message says 'insert a valid sim card'. I don't understand why its reoccurring. The moment I hit restart its ok but it re-occurs again. The mobile is locked by the provider. I recently opened a new app and have been receiving this error message ever since. What should I do? Please Help!

 

[Thom]

Welcome to Android Forums. I moved your question to the area where your phone is discussed.

... Thom