I updated the iphone 4s to ios 8 but I can't access it because when I insert any sim to activate it. It shows
sim not valid
The sim card that you currently have installed in this iphone is from a carrier that is not supported under the activation policy that is currently assigned by the activation server. This is not a hardware issue with the iphone. Please insert another SIM card from a supported carrier or request that this iphone be unlocked by your carrier. Please contact Apple for more information.