My iphone 4s has developed an invalid sim message I can't make any calls or recieve any at present
My Iphone 4s has developed a fault invalis sim any help out there how to fix this
iPhone 4S, iOS 7.1
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- Update your iPhone to the latest version of iOS.
- Toggle Airplane mode On and Off.
- Try turning iPhone off and then on again.
- Check for a carrier settings update. Tap Settings > General > About. If an update is available, a prompt will appear.
- Remove the SIM Card and verify that it is a valid, carrier-manufactured SIM. Also verify that it is not damaged, worn, or modified. Then reinsert it.
- Restore the iPhone.
If you still are unable to resolve this issue, contact Apple support for further assistance.
copied from Troubleshooting iPhone hardware